Rachel's 30th birthday prompts the friends to reminisce about their own 30th birthdays.

Joey's character on a daytime drama becomes more prominent to the chagrin of the show's diva star. Phoebe and Rachel argue over who should return a sexy man's misplaced cell phone to him.

Chandler finds out who Monica really wanted to have sex with on the night they became lovers. Ross is furious after Rachel teaches Ben practical jokes.

Monica battles another shopper for the perfect wedding dress. Ross and Joey compete for the same woman.

Joey overreacts at a daytime drama awards show.

After a disastrous blind date, single parents Lauren and Jim agree on only one thing: they never want to see each other again. When they sign up separately for a family vacation, they're stuck sharing a suite at an African safari resort.

Looking to get friendly with Barry Kripke to gain access to a piece of high-tech lab equipment, Sheldon develops a flowchart process to make friends.

When Sheldon loans money to Penny so she can pay her rent, it leads to Leonard coming face-to-face with her ex, Kurt.

A visit from Leonard's mother ends up bringing him and Penny closer.

Paintball leads to a squabble between Sheldon and Penny as well as romance between Howard and Leslie.

The gang is thrilled when they see Terminator: The Sarah Connor Chronicles' Summer Glau is also aboard their train to San Francisco for a scientific symposium. Sheldon frets over having forgotten a paper he wants to present to George Smoot.

Penny's business selling hair accessories out of her apartment gets out of hand when an over-caffeinated Sheldon takes charge.

Penny feels threatened when another sexy woman moves into the apartment building and angered when she senses the guys are being taken advantage of.

A fellow comic book enthusiast's hitting on Penny leads to Leonard, Raj and Howard going to a bar's Ladies' Night.

Leonard and Raj take Wolowitz to Las Vegas to help him get over his break-up with Leslie. Sheldon, home alone and looking forward to it, locks himself out and has only one other place to stay: Penny's.

Leonard is torn between being honest or self-serving when Stuart asks his advice for an upcoming second date with Penny. Wolowitz realizes there's a crucial error in a toilet he designed for the International Space Station.

After a disastrous blind date, single parents Lauren and Jim agree on only one thing: they never want to see each other again. When they sign up separately for a family vacation, they're stuck sharing a suite at an African safari resort.

Meet 9-year-old Sheldon and his family on the series premiere! Sheldon learns that his high intelligence isn't always helpful growing up in East Texas, where church and football are king.

Sheldon goes on a quest to make his first friend.

Sheldon's faith is shaken when his dad goes to the hospital.

Sheldon refuses to eat solid food after a choking scare.

Sheldon helps his father coach the football team.

Sheldon is determined to prove a NASA rep wrong.

Monica's gorgeous cousin unwittingly wreaks havoc on Chandler and Ross. Rachel and Phoebe hastily plan a surprise bridal party for Monica.

Rachel reveals a titillating secret about her and a former sorority sister. Ross and Chandler compete for wedding tuxedos.

As Monica and Chandler prepare their wedding vows, they and their friends reminisce.

Chandler confronts his estranged cross-dressing father. Rachel gets into trouble driving Monica's Porsche.

On the eve of the wedding, Ross searches for missing Chandler, who has doubts, while the girls distract unsuspecting Monica.

Monica remains blissfully unaware of the potential disasters on her wedding day.

The reception following Monica and Chandler's wedding is almost upstaged by the news that a member of the group might be pregnant.

Rachel debates whether she should break the news to her baby's father.

The real father of Rachel's baby is revealed. Monica and Chandler struggle to make their honeymoon flight.

Ross reveals that he videotaped a sexual encounter between Rachel and him.

Ross is horrified when Rachel goes on a date with a soap-opera star. Phoebe is attracted to a clumsy chef whom Monica wants to fire.

At Monica's Halloween party, Phoebe meets her twin sister's fiance and finds that she is attracted to him.

The guys receive a prestigious offer to work over the summer at the North Pole, and Penny's resultant behavior leaves Leonard unsure if he should go.

Discovering Leonard, Raj and Howard fudged the results of his Arctic research expedition, a disgraced Sheldon heads home to Texas.

Howard takes Raj along to check out the Goth dating scene. Sheldon uses chocolate as part of a behavior modification experiment on Penny.

Facing a return to India, Raj needs a job desperately enough to consider working for Sheldon. Meanwhile, Howard becomes a third wheel to Leonard and Penny.

Sheldon looks forward to squaring off against an actor from the Star Trek universe he holds enmity towards in a fantasy card game tournament. Wolowitz cashes in on an old pact with Leonard to get Penny to set him up with a friend of hers.

Leonard, hoping to fit in with Penny's football-loving friends, gets tutored in the sport by Sheldon. Raj is infuriated when Wolowitz's skirt-chasing leads to the loss of his prized patang.

Leonard and Penny's first big fight sees Sheldon playing mediator due to childhood trauma that's left him with an inability to be around loud verbal conflicts.

With the rest of the gang off on a desert camping trip to view the Leonid meteor shower, Sheldon must play hero after Penny slips in the tub and dislocates her shoulder.

Barry Kripke pranks Sheldon during his spot on NPR, leaving him with a taste for vengeance. Wolowitz, pressured by Bernadette to define their relationship, gets advice from a fantasy version of Katee Sackhoff.

Penny seeks Sheldon's help to better comprehend Leonard's physics work. Wolowitz sees green when Leonard invites Bernadette to watch an experiment.

A Christmas visit from his mother has Leonard discovering she's kept a lot of news from him that she shares with Sheldon and worrying if she'll approve of his romance with Penny.

Leonard is aghast to find out a secret of Penny's: she believes in psychics. Meanwhile, Sheldon tries to assist Koothrappali in picking up a girl at a university party.

The Smiths prepare for the arrival of Stan's half-brother's family for Thanksgiving.

Stan's plan for a perfect Thanksgiving watching football in his underwear is thwarted when Francine invites her parents to join them. Francine's mom encourages Hayley to get back on the dating scene and invites an eligible bachelor over.

Overlooked for promotion for twenty years, Stan decides to woo the Senator who supervises the CIA task force. Stan makes Steve go to the same private academy as the Senator's daughter, but Steve ditches school and Roger takes his place.

When Steve has trouble crossing over into the "cool kids" social circle, Klaus and Roger place their bets to see how quickly Roger can make him cool.

After Snot professes his love for Hayley and gets shot down, Steve and Roger devise a plan to cheer him up. Roger dresses up as Steve's cousin from New Jersey, Jenny Fromdabloc, and Snot falls hard for her.

Stan and Francine fight over how to redecorate the house. It goes so far that they split the house down the middle and try to live without each other.

Francine gets a job at Stan's office, which cramps Stan's style and his ability to flirt with co-workers. When Francine retaliates with a little flirting of her own, war breaks out at work.

Stan spends some quality father-son time with Steve at the local zoo, but things go wrong when Steve slips into a gorilla exhibit.

Stan battles an evil hot tub bent on killing his family.

This week is dedicated to the Almighty ... the Almighty Wipeout course, that is. Pastor's kids, country boys and fashion models battle it out for $25,000 and Wipeout immortality.

Bowlers, Carnival Workers, and Flag Footballers armed with Gronk's advice battle it out with the hopes of winning $25,000 -- and for the Carnival Crew, a chance to conquer the greatest obstacle course on Earth!

Meemaw refuses to give George Sr. her brisket recipe.

George takes his sons to see a space shuttle launch.

Sheldon tutors his brother when his grades threaten football.

Sheldon interviews with a school for gifted children.

A trip to Sunday school inspires Sheldon to study religions.

Mary and the twins move in with Meemaw after a fight.

Rachel wants to find her own apartment. Phoebe is ecstatic when Eric dumps Ursula to date her.

Rachel tells her belligerent father that she is pregnant with Ross' child.

Monica encounters a high-school friend and invites him to Thanksgiving Day dinner.

Chandler is angry when Monica buys expensive boots. Phoebe tries to get tickets to a Sting concert.

Ross' new girlfriend orders Christmas cards with a photo of them on the cover.

Rachel joins Joey for a night out in order to prepare him for a big date.

Monica blabs her suspicions when she mistakenly believes Joey is infatuated with Phoebe.

Sheldon's germophobia lands him in detention.

Sheldon and Missy are left home alone for the first time.

Sheldon and Tam make a new friend.

Jason Alexander guest stars as Sheldon's drama teacher.

Sheldon faces an unlikely bully.

Sheldon declares his independence from Mary.

Joey realizes his intense feelings for Rachel are excluding Ross from the joys of impending fatherhood.

Monica intends to host a cozy Thanksgiving feast in her apartment with her friends but her plans go awry, and the feast becomes a fiasco.

Rachel makes a painful discovery concerning Ross. Monica's new boss gives her an impossible task.

On Thanksgiving, a good-natured football game between the friends reveals some serious rivalries.

On Thanksgiving, Joey wants to punish Chandler for kissing Kathy. Monica gets a surprise when she visits an eye doctor.

The friends find out about Monica's worst Thanksgiving ever.

Joey becomes exasperated from hiding Chandler and Monica's secret. Ross gets in trouble when he expresses his rage.

On Thanksgiving, Chandler tries to gain favor with Monica's parents but an old secret involving Ross causes problems. Undomestic Rachel's dessert proves intriguing.

Chandler's irrational fear causes problems when Phoebe brings home a cute dog. Rachel's assistant gives her a Thanksgiving surprise.

Monica encounters a high-school friend and invites him to Thanksgiving Day dinner.

Rachel has a bone to pick with her self-centered sister on Thanksgiving.

Monica prepares a Thanksgiving feast for the gang, then becomes enraged when everyone shows up late. Phoebe convinces Rachel to enter Emma in a baby beauty contest.

Sheldon and Howard wager comic books over a cricket's species. Meanwhile, a less-than-perfect romantic night agonizes Leonard and Penny.

A robbery of their apartment sees Leonard and Sheldon call on their friends to devise a security system.

Stuck on the solution to a physics problem, Sheldon seeks a number of alternative approaches to change his thinking and free the mental block -- including working with Penny at The Cheesecake Factory.

When Leonard is offered a trip to Switzerland on Valentine's Day to see a particle accelerator, he must choose between taking Penny or Sheldon.

An appearance in traffic court comes at the worst possible time for Sheldon, the same day Stan Lee is appearing at the comic book store.

The guys go to a garage sale and find a ring from the Lord of the Rings films, and the rare find threatens their friendship.

Sheldon's fear of speaking in front of large groups threatens his ability to accept an award, so the gang tries to help him get ready for the big night.

Sheldon gets to square off at the bowling alley against nemesis Wil Wheaton. Meanwhile, Leonard's miffed when Penny doesn't respond the way he hoped after saying "I love you."

Monica intends to host a cozy Thanksgiving feast in her apartment with her friends but her plans go awry, and the feast becomes a fiasco.

Rachel makes a painful discovery concerning Ross. Monica's new boss gives her an impossible task.

On Thanksgiving, a good-natured football game between the friends reveals some serious rivalries.

On Thanksgiving, Joey wants to punish Chandler for kissing Kathy. Monica gets a surprise when she visits an eye doctor.

The friends find out about Monica's worst Thanksgiving ever.

Joey becomes exasperated from hiding Chandler and Monica's secret. Ross gets in trouble when he expresses his rage.

On Thanksgiving, Chandler tries to gain favor with Monica's parents but an old secret involving Ross causes problems. Undomestic Rachel's dessert proves intriguing.

Chandler's irrational fear causes problems when Phoebe brings home a cute dog. Rachel's assistant gives her a Thanksgiving surprise.

Monica encounters a high-school friend and invites him to Thanksgiving Day dinner.

Rachel has a bone to pick with her self-centered sister on Thanksgiving.

Monica prepares a Thanksgiving feast for the gang, then becomes enraged when everyone shows up late. Phoebe convinces Rachel to enter Emma in a baby beauty contest.

Howard's mother has a say when he and Bernadette host Thanksgiving dinner for the gang.

An electrical short thaws the last meal that was cooked by Mrs. Wolowitz, and the gang ponders what to do with it, while Sheldon and Leonard's work is featured in a magazine, but only one receives credit.

Now just friends, Sheldon and Amy spend Thanksgiving at the aquarium, a reluctant Wolowitz volunteers at a soup kitchen with Bernadette, Raj and Emily, and Penny realizes that Leonard knows a bit more about her than he's let on.

Sheldon and Howard plan birthday celebrations for Amy and Halley, respectively. Leonard receives a Christmas letter from his brother that causes him to spiral out about his own lack of accomplishments.

After a tornado whisks Kansas farm girl Dorothy to a magic land, she must travel to the Emerald City for help in getting back home.

The conductor of a train to the North Pole guides a boy who questions the existence of Santa Claus.

Monica prepares a memorable St. Valentine's Day for Chandler with sexy lingerie and X-rated entertainment.

Joey tells Rachel that he is in love with her.

Rachel devises a lie about her unborn child that she hopes will break the silence between her and Joey. Phoebe reads tea leaves and predicts she will soon encounter the man of her dreams.

Phoebe brings her annoyingly upbeat boyfriend to the 35th anniversary of Monica and Ross' parents, who urge Ross and pregnant Rachel to pretend to be married.

When Soap Opera Digest requests an interview, Joey enlists his friends to make sure he does not say anything that could cost him his role.

During her baby shower, Rachel realizes she is unprepared to be a mother and accepts her mother's offer to move in to help with the child.

A food critic blasts Monica's cooking in a newspaper review. A cute saleswoman riles Rachel when she flirts with Ross, and Phoebe coaches Chandler for a job interview.

Overdue Rachel tries everything to rush the delivery of her baby.

The friends cause havoc in the maternity ward as Rachel begins childbirth.

The friends cause havoc in the maternity ward as Rachel begins childbirth.

Joey finds himself engaged to Rachel soon after she delivers her baby girl, while Phoebe assumes Ross is the one who proposed.

Joey seeks forgiveness from Ross, while Rachel tries to quell Emma's incessant crying.

Emma's pediatrician drops her as a patient because of Rachel's constant calls.

The conductor of a train to the North Pole guides a boy who questions the existence of Santa Claus.

After a tornado whisks Kansas farm girl Dorothy to a magic land, she must travel to the Emerald City for help in getting back home.

As a baby, Buddy crawls into Santa's toy bag and is whisked off to the North Pole, where he is raised as an elf. A misfit who grows to be three times the size of his elf family, Buddy heads to his birthplace to seek out his roots.

As a baby, Buddy crawls into Santa's toy bag and is whisked off to the North Pole, where he is raised as an elf. A misfit who grows to be three times the size of his elf family, Buddy heads to his birthplace to seek out his roots.

As a baby, Buddy crawls into Santa's toy bag and is whisked off to the North Pole, where he is raised as an elf. A misfit who grows to be three times the size of his elf family, Buddy heads to his birthplace to seek out his roots.

As a baby, Buddy crawls into Santa's toy bag and is whisked off to the North Pole, where he is raised as an elf. A misfit who grows to be three times the size of his elf family, Buddy heads to his birthplace to seek out his roots.

As a baby, Buddy crawls into Santa's toy bag and is whisked off to the North Pole, where he is raised as an elf. A misfit who grows to be three times the size of his elf family, Buddy heads to his birthplace to seek out his roots.

As a baby, Buddy crawls into Santa's toy bag and is whisked off to the North Pole, where he is raised as an elf. A misfit who grows to be three times the size of his elf family, Buddy heads to his birthplace to seek out his roots.

As a baby, Buddy crawls into Santa's toy bag and is whisked off to the North Pole, where he is raised as an elf. A misfit who grows to be three times the size of his elf family, Buddy heads to his birthplace to seek out his roots.

As a baby, Buddy crawls into Santa's toy bag and is whisked off to the North Pole, where he is raised as an elf. A misfit who grows to be three times the size of his elf family, Buddy heads to his birthplace to seek out his roots.

As a baby, Buddy crawls into Santa's toy bag and is whisked off to the North Pole, where he is raised as an elf. A misfit who grows to be three times the size of his elf family, Buddy heads to his birthplace to seek out his roots.

As a baby, Buddy crawls into Santa's toy bag and is whisked off to the North Pole, where he is raised as an elf. A misfit who grows to be three times the size of his elf family, Buddy heads to his birthplace to seek out his roots.

As a baby, Buddy crawls into Santa's toy bag and is whisked off to the North Pole, where he is raised as an elf. A misfit who grows to be three times the size of his elf family, Buddy heads to his birthplace to seek out his roots.

As a baby, Buddy crawls into Santa's toy bag and is whisked off to the North Pole, where he is raised as an elf. A misfit who grows to be three times the size of his elf family, Buddy heads to his birthplace to seek out his roots.

Clark Griswold's efforts to have a good old-fashioned family Christmas take a turn for the worse in this holiday classic.

Clark Griswold's efforts to have a good old-fashioned family Christmas take a turn for the worse in this holiday classic.

Neighbors in a New England town go to war after one adorns his house with enough Christmas lights to make it visible from space.

Big Momma is hired to go deep undercover as the headmistress of the Atlanta Girls' School for the Arts, and he brings along his son to go undercover as a student in the school.

Monica fears Chandler has a sexual fetish involving sharks.

Famished Phoebe waits for tardy friends to arrive at her birthday dinner.

Ross ridicules Rachel's choice of a male nanny.

Chandler and Joey find a videotape while checking out Richard's apartment. Ross sings Emma an off-color lullaby.

Rachel has a bone to pick with her self-centered sister on Thanksgiving.

Rachel impulsively gives her telephone number to a handsome guy but worries he will call when Ross is there.

Monica fears the worst when she learns Chandler will be spending Christmas in Tulsa working on a deadline with a beautiful co-worker.

Rachel crosses swords with her temporary replacement at the shop. Phoebe wreaks havoc on the set of Joey's soap opera.

Monica invites Rachel's workplace rival to her birthday party. Joey flirts with Emma's new nanny, and Phoebe and Mike take care of a litter of rats.

Monica exults in the applause she receives on karaoke night, unaware that the cheering audience can see through her blouse.

Thor is imprisoned on the other side of the universe without his mighty hammer and finds himself in a race against time to get back to Asgard to stop Ragnarok, the destruction of his homeworld and the end of Asgardian civilization.

Subsequent to Leonard and Penny's break-up, Sheldon tries to hide from Leonard and the gang that he had a friendly spaghetti dinner at Penny's.

Sheldon hosts a visiting female physicist, but her intelligence seems matched by her libido.

A squabble over the thermostat setting leads to Leonard going over to Penny's and recounting for her the story of how he met and moved in with Sheldon.

Howard and Raj try to find the perfect match for Sheldon by setting him up on an Internet dating site. Seeing her new boyfriend interact with the gang makes it clear to Penny that she can't go back to dating dumb jocks after dating Leonard.

Howard uses a robotic arm for his own pleasure. Sheldon goes on a date with Amy Farrah Fowler, his first date ever, and Penny finds herself accompanying them.

Sheldon calculates that he'll be dead before technology exists to download his consciousness into a robot, so he goes on a binge of healthy living and ultra-safety.

Sheldon breaks up with Amy Farrah Fowler, and the guys worry when he starts replacing her with cats.

Wolowitz is embarrassed when a secret of his is revealed, and Sheldon and Raj battle at work.

Sheldon meets Amy Farrah Fowler's mother and comes to the realization he no longer wants to see Amy, and Leonard realizes everyone is in a relationship except for him.

When Raj's sister has a one-day layover, he forbids the others from hooking up with her, unaware she and Leonard already did long ago.

Our Wipeout teams are THIRSTY. They include a team of PDA-loving first responders and another team begging Jackie Chan to adopt them. Only by completing the toughest Wipeout course in history can their thirst for $25,000 be quenched.

Thor is imprisoned on the other side of the universe without his mighty hammer and finds himself in a race against time to get back to Asgard to stop Ragnarok, the destruction of his homeworld and the end of Asgardian civilization.

Two salesmen, Wheeler and Danny, trash a company truck on an energy drink-fueled bender. Upon their arrest, the court gives them a choice: do hard time or spend 150 service hours with a mentorship program.

Sheldon dismantles the refrigerator to stop an annoying hum and then must get a paper route to pay for the repairs.

When Dr. Sturgis bonds with Paige, another 10-year-old genius, Sheldon's jealousy leads Meemaw to intervene. Meanwhile, Mary invites Paige's family over for a play date.

When Mary's faith is shaken by a tragedy in the community, Sheldon becomes an unlikely ally.

When George Sr. asks Sheldon to keep a secret from Mary, the stress of not being honest drives Sheldon to hide out at Tam's for his first sleepover.

Dr. Sturgis recommends Sheldon and Missy for a university research study on twins, and Mary is unhappy when the test results go to Sheldon's head.

When Meemaw gives Sheldon his first video game, it takes over their lives. Meanwhile, George Sr. gets jealous when Georgie bonds with Herschel at the auto shop.

Joey and Phoebe conspire to send Rachel and Ross on disastrous blind dates.

Joey stumbles upon a way to impress a famous actor during an audition. Ross learns the identity of a long-ago mugger, and Chandler accepts an internship at a shoe company.

Both Monica and Chandler secretly approach Joey for a loan. Phoebe invites Mike to move in with her, and Rachel baby-proofs the apartment.

Ross and Chandler trade barbed insults on their alma mater's Web site.

The gang buys scads of lottery tickets for the multimillion-dollar jackpot.

Rachel's visit to a soap opera set inspires her to dream about Joey. Chandler takes Ross on a weekend getaway after Monica cannot take time off from work.

Ross invites an attractive paleontologist to a rooftop Days of Our Lives party being thrown by Joey.

Monica and Chandler run into an old acquaintance when they secretly go to a fertility clinic. Ross helps Joey woo the same professor he wants to date.

Monica and Chandler interview unsuspecting candidates, hoping to find the right man to father their baby.

The gang heads to Barbados for a paleontology convention where Ross is the keynote speaker. David prepares to propose to Phoebe, but ex-boyfriend Mike is not yet out of the picture.

The gang heads to Barbados for a paleontology convention where Ross is the keynote speaker; David prepares to propose to Phoebe, but ex-boyfriend Mike is not yet out of the picture.

In Barbados, Monica, Chandler and Phoebe eavesdrop on their friends' passionate encounters. Monica styles her hair to look like a blowfish, and Phoebe and Mike rekindle their romance.

The rest of the gang is interviewed by the FBI for Wolowitz's security clearance with Sheldon accidentally letting slip some damaging information.

The guys camp out in line to see a print of Raiders of the Lost Ark with 21 extra seconds and are outraged to see Wil Wheaton and his friends being allowed to skip the line. Penny and Bernadette invite Amy to their girls night.

Penny asks Leonard to lie to her visiting father, while Howard, Raj and Bernadette spend all night looking through a telescope.

Amy crushes on one of Penny's dim ex-boyfriends, Zack. Raj and Wolowitz argue over who'd be the better superhero.

The guys get Zack and Penny to join their Justice League costume for a New Year's Eve bash at the comic book store.

Their friendship becomes strained when Sheldon tries to take over Leonard's creation of a smartphone application that solves differential equations.

Howard is jealous when Bernadette runs into her old boyfriend at a science event they're attending.

Sheldon wants acting lessons from Penny, hoping they will make him a better teacher.

After meeting at a fundraising gala, an aged but wealthy Caltech donor makes Leonard ponder if he's willing to have sex with her to secure another donation.

Howard contemplates a serious decision in his relationship with Bernadette, and Leonard and Raj's sister start seeing each other again.

Sheldon is in a crisis when he realizes he's not the epicenter of the group, so he decides to find new friends.

Leonard has a tough choice to make when Priya asks him to stop spending time with Penny, forcing him to choose between the two women, and Howard keeps pestering Sheldon with a magic trick.

When the Smiths decide to stay home during a hurricane that hits Quahog, Stoolbend and Langley Falls, they must fight tooth and nail to survive.

After he's appointed Steve's legal guardian, Roger has Principal Lewis fired for letting Steve break the school's rules. Stan and Fran vacation at a waterpark.

Stan arranges for Principal Lewis to marry Superintendent Riggs so he can finally be a best man at a wedding. Roger's new shorts attract the interest of Ricky Martin.

Stan uses an avatar of a hot girl to bond with Steve. Roger plots a violent end for frat brothers who stiffed him out of $20 for a limousine ride.

Francine is disgusted when Stan reestablishes contact with a crush from CIA boot camp. Bullock hires a bounty hunter to capture Roger. Steve wears Hayley's panties after concluding they bring him luck.

Father Donovan holds a Christmas play at the mall and casts Stan as Santa Claus and Roger as Jesus. After they get in a fight and cause a scene, Stan is kicked out of the church. Hayley and Jeff adopt a child who turns out to be possessed.

With Roger's help, Steve dresses up as a superhero to prove his bravery to his father. When Stan discovers that Fran may be pregnant, he hopes the infant will turn out to be the brave child he never had.

Hoping to show Steve the value of hard work, Stan gets Steve a job at a country club. Francine struggles to come up with her own catchphrase.

Stan joins Roger and Steve's fictional detective agency, but he ruins the fun by being extremely incompetent at his job. Roger demands Steve fire Stan, but Steve cannot bring himself to do it and lies to Roger.

Put on your best tiara because royalty is gracing the Wipeout course as the Prince and Brynn try to add $25,000 to the royal coffers. But the Mud Runners, Blind Daters and Never Been Tripped will give them a run for the money!

Mary clashes with Sheldon's drama teacher Mr. Lundy over plans for a Halloween haunted house fundraiser for the church. Also, Georgie falls for a rebellious teenage girl that Sheldon is tutoring.

Sheldon gets into trouble with fellow child genius Paige at the Science Museum, while George Sr. is forced to play therapist to Paige's bickering parents, Barry and Linda. Meanwhile, Mary, Georgie and Missy help Meemaw with a garage sale.

Sheldon studies his family for a psychology project when their Thanksgiving dinner turns into a family fight after George Sr. is offered a job in Oklahoma.

Bazinga is born! When Sheldon learns that people with stunted childhoods can turn into social outcasts, he tries to act like a kid. Also, Meemaw and Dr. Sturgis's relationship is tested when she teaches him how to drive.

While Missy unknowingly becomes Sheldon's test subject, Georgie joins Mary's Bible study to spend more time with his crush, Veronica.

Sheldon uses his new friendship with the school bully to boss Georgie around. Also, Missy steals Meemaw's makeup for Picture Day.

Ross drinks too much alcohol at dinner with Rachel, Joey and Charlie. Frank Jr. cannot cope with his precocious triplets.

Rachel and Joey nervously anticipate their first real date. Monica and Phoebe try to avoid an obnoxious friend with a fake British accent, and Ross emerges from a tanning booth with a two-toned appearance.

An X-rated cake is delivered to Emma's first birthday party.

Rachel convinces her sister to baby-sit over Ross' protests, and Joey writes a letter to an adoption agency on Monica and Chandler's behalf.

When Ross interviews with Charlie's ex-boyfriend for a prized grant, the doctor makes a shocking stipulation.

Monica and Chandler fuss over their apartment as they expect a visit from the adoption worker. Phoebe and Mike opt for a small wedding and donate the extra money to a children's charity.

Monica prepares a Thanksgiving feast for the gang, then becomes enraged when everyone shows up late. Phoebe convinces Rachel to enter Emma in a baby beauty contest.

A prospective birth mother labors under a misconception about Monica and Chandler's respective occupations.

Rachel and Phoebe spot Chandler getting into a vehicle with a mysterious blond woman.

Joey appears as a celebrity contestant on $100,000 Pyramid. Monica and Rachel hire an ungainly stripper for Phoebe's bachelorette party.

A blizzard causes Phoebe and Mike's wedding to spiral out of control. Uptight Monica steps in as her friend's wedding planner, then drives everyone crazy.

Monica and Chandler show Erica the sights but also learn their baby's biological father might be an unsavory character. Joey begs Phoebe to teach him how to speak French before an audition.

The guys become sleuths to find out who hacked Sheldon's online-game account.

Sheldon and Amy decide to start rumors about themselves as a social test. Meanwhile, Howard takes his relationship with Bernadette to an even higher level.

Priya uses her legal expertise to rip apart Sheldon's roommate agreement, and the women take the flustered Sheldon out dancing.

Raj makes an attempt to cure his phobia of talking to women, and Penny spies on Leonard and Priya with the help of Bernadette.

Mrs. Wolowitz ends up in the hospital after Howard tells her he's marrying Bernadette. While there, Leonard stresses over Penny and Priya warming up to one another.

Raj moves in with Sheldon when Leonard and Priya's Star Trek bedroom fantasy is too much for him, and the guys tease Howard when Bernadette gets her PhD, making Howard the only one without a doctorate.

On the fifth season premiere, Penny worries that she's screwed things up permanently with her friends after her night with Raj, while Sheldon takes command of the paintball team.

A battle of wills between Sheldon and Penny leaves Amy caught in the middle, while Leonard tries to spice up his long-distance relationship with Priya (Aarti Mann).

Attending a co-worker's wedding, Leonard and Amy (Mayim Bialik) get to know each other better, while Howard and Bernadette spend the weekend with Mrs. Wolowitz!

When Raj is upset he's the only one of the four guys who's not in a relationship, Penny sets out to find the perfect date, introducing him to Emily, a girl he can actually talk to!

Sheldon and Leonard get invited to a housewarming party at Wil Wheaton's house. Howard gets an out-of-this-world opportunity!

Sheldon craves attention from his visiting mother.

Sheldon tries to spook his friends on Halloween.

Bernadette and Penny shop for wedding dresses without Amy.

Our Wipeout teams are THIRSTY. They include a team of PDA-loving first responders and another team begging Jackie Chan to adopt them. Only by completing the toughest Wipeout course in history can their thirst for $25,000 be quenched.

When Sheldon gets sick and has to spend a few days in the hospital, he turns into the world's worst patient and his behavior takes a toll on everyone. Also, Missy gets a taste of what life would be like without her twin.

While Sheldon attempts to build a nuclear reactor to power the neighborhood, Georgie is heartbroken when he learns that Veronica has a boyfriend. Also, a university party gets heated when Dr. Linkletter flirts with Meemaw.

Sheldon and Dr. Sturgis have their first fight when Dr. Sturgis marks a question wrong on Sheldon's test. Mary takes over for Pastor Jeff when he's out sick.

Things spiral out of control when Sheldon boycotts his favorite bread company and ends up on the local news. Meanwhile, Georgie offers Veronica a shoulder to cry on when she's dumped by her boyfriend.

Inspired by his hero, Albert Einstein, Sheldon tries his hand at the violin. Also, Mary and Meemaw secretly buy a pregnancy test when Mary thinks she's pregnant.

Sheldon moves in with Dr. Sturgis for the weekend to see what his life would be like in college. Also, a lonely Mary tries to bond with the other Coopers during Sheldon's absence.

Rachel goes to a job interview at a restaurant and winds up sitting next to her current boss. Joey feels abandoned because Monica and Chandler are leaving.

Ross tries to win back Rachel's job with her former fashion employer. Phoebe tries to keep Joey from learning about his agent's death, and Monica and Chandler make a horrifying discovery.

One of the guys becomes offended when Rachel does not give him the same goodbye she gives the others.

The six friends say goodbye and embark on the next chapters of their lives.

The six friends say goodbye and embark on the next chapters of their lives.

After Rachel leaves her fiance at the altar, she moves in with Monica and finds that independence is not so easy, particularly without Daddy's credit cards.

Ross is stunned to learn his ex-wife is pregnant with their child. Monica's dinner for her overly critical parents is a disaster.

The group loves Monica's new boyfriend. Chandler resumes smoking, and Phoebe receives a large sum of money unexpectedly.

While the men attend a hockey game and end up at a hospital, the women spy on President Clinton's top aide, George Stephanopoulos, who lives across the street. Rachel receives her first paycheck.

While Phoebe and Chandler end their respective romantic relationships, Rachel and Ross do laundry together on their first date.

Joey gets a film role as a stand-in for Al Pacino's butt. Ross tries to be less conservative. Chandler has an affair with a married woman.

A citywide power outage leaves Chandler stranded in the vestibule for an automatic banking machine with gorgeous model Jill Connick. Ross tries to ask Rachel out on a date. Joey learns Monica used to be infatuated with him.

Sheldon must overcome his fear of birds.

Sheldon becomes jealous when Stuart asks Amy for a date.

Leonard comes face-to-face with his high school bully.

Sheldon gets in trouble with Amy, and it's up to Penny to teach him how to be a better boyfriend. Howard, meanwhile, must come to grips with Bernadette's dislike of children.

Everything might change when Leonard offers Penny a spur of the moment invitation to a romantic dinner for two on the 100th episode of the series.

Leonard and Penny "beta test" their relationship.

Sheldon's selfish demands force Leonard to reconsider their friendship. Meanwhile, Howard tries to pick his astronaut nickname. NASA astronaut Mike Massimino guest stars.

When Sheldon is forced to take a vacation by the university, he goes to work with Amy in her neurobiology lab.

Our Wipeout teams are THIRSTY. They include a team of PDA-loving first responders and another team begging Jackie Chan to adopt them. Only by completing the toughest Wipeout course in history can their thirst for $25,000 be quenched.

Unhappy that school funds are going toward football rather than academics, Sheldon decides to run for class president.

Georgie is thrilled when Veronica stays at the Coopers' for a few days. Meanwhile, Meemaw and Dr. Sturgis celebrate their one-year anniversary.

The Coopers help a brokenhearted Pastor Jeff through a rough patch in his marriage. Meanwhile, Sheldon pressures church members for donations when Mary takes him to work for a day.

Sheldon invites the entire school to a party for the Nobel Prize announcements. Meanwhile, Meemaw learns more about Dr. Sturgis's past, and Georgie's desire for cable TV leads to a standoff between him and his dad.

Mary worries about Sheldon's mental health.

Sheldon takes his education into his own hands.

When Ross and Monica's grandmother dies, the whole gang attends the funeral service. Chandler questions his sexual persona when a co-worker wants to arrange a date for him with another guy.

Monica intends to host a cozy Thanksgiving feast in her apartment with her friends but her plans go awry, and the feast becomes a fiasco.

The friends promise to celebrate New Year's Eve without dates but soon all their plans change. Ross gets a pet monkey.

Chandler's flamboyant mother comes to New York for a visit. Phoebe and Monica cause a traffic accident.

Rachel's Italian boyfriend tries to seduce Phoebe. Rachel accidentally reveals a secret to Ross. Monica's aunt refuses to take the lasagnas she ordered from Monica.

Chandler sees Rachel nude. Joey learns his father is having an affair.

On Valentine's Day, Ross meets his ex-wife while on his first date in nine years. The girls rebel by burning mementos of past relationships.

A restaurant owner interviews Monica for a chef's position. Ross asks Joey how to talk dirty to women.

Phoebe's twin sister causes confusion and conflict. Ross attends childbirth classes with his ex-wife and her girlfriend.

Rachel and Monica squabble over two handsome doctors. Ross ponders his impending fatherhood with his own father.

The women lose money in a poker game with the men. After getting advice from a champion card player, they demand a rematch.

Rachel accidentally lets Ross' pet monkey escape, and the friends form a search party. Rachel learns that her former best friend is engaged to marry Rachel's former fianc?.

Our Wipeout teams are THIRSTY. They include a team of PDA-loving first responders and another team begging Jackie Chan to adopt them. Only by completing the toughest Wipeout course in history can their thirst for $25,000 be quenched.

When a corner office at the University opens up, Sheldon must compete for it with his office nemesis, Barry Kripke. Meanwhile, Penny receives an unusual gift from Amy.

A change in Sheldon's routine forces him to re-evaluate his entire life, when his barber is sick. Meanwhile, Howard rethinks his decision to go into space after astronaut training.

Sheldon chooses to participate in a guys-only weekend Star Wars gaming marathon rather than go with Amy to her aunt's birthday party -- and gets a lesson from Penny and Amy.

It's a dream come true for Sheldon when he has a close encounter with his hero, Mr. Spock -- legendary sci-fi icon Leonard Nimoy.

Sheldon has a chance to meet his hero, Stephen Hawking.

Howard's wedding plans are in jeopardy after the guys (and Wil Wheaton) throw him a bachelor party and details of his sexual history are leaked online.

When NASA reschedules Howard's mission and puts his wedding plans in jeopardy, he's forced to face his fears and Bernadette's dad (Casey Sander).

When Howard and Bernadette decide they want to be married before his NASA space launch, the gang rushes to put on a wedding, on the fifth season finale.

On the sixth season premiere, Howard discovers that he can't escape his mother -- even in space! Back on earth, meanwhile, Raj turns his existence as a third wheel into an art form.

When Sheldon learns that Penny is thinking about breaking up with Leonard, he tries to intervene. Meanwhile, Howard is being picked on in space by the other astronauts.

Amy's nervous when Sheldon hires Alex, a female assistant.

Howard returns from space -- without the welcome he wanted.

Justin Timberlake and Mila Kunis star in this enticing romantic comedy about a couple of friends challenging the clichés of love.

Sheldon leaves town after a fight with Meemaw and his parents.

On a science break, Sheldon discovers The Lord of the Rings.

Dr. Sturgis returns from the mental hospital.

Missy tries out for the baseball team.

Sheldon starts the first internet flame war.

The university tries to recruit Sheldon, through George.

Rachel reunites with her duplicitous ex-fiance. Chandler agonizes about a woman who doesn't call him after the first date.

Monica meets a woman who helps her live out her fantasies. Ross' pet monkey becomes sexually mature and makes everyone crazy.

Monica finds out more than she wants to know about her latest love. Chandler's friends at work treat him differently since his promotion. Ross' ex-wife begins giving birth.

When Carol gives birth, Ross and Susan almost miss the event. Joey befriends an unmarried pregnant woman.

Rachel finds out about Ross' secret love for her but another surprise awaits her.

Rachel gets an unpleasant surprise when Ross returns home. Phoebe has varied success cutting the friends' hair.

Phoebe unwittingly disgusts everybody. Joey competes with a fellow salesman.

The downstairs neighbor dies and bequeaths his strange possessions to Monica and Rachel.

Everyone is surprised when Phoebe's husband shows up.

The friends want to give Ross a birthday party but disagree about money. Monica gets promoted and learns a tough lesson.

Joey and Chandler try to attract women with baby Ben. Phoebe gets terminated from her singing job and replaced by a professional, Stephanie.

Dramatic developments occur in Ross and Rachel's relationship. Chandler regrets asking Monica to help him lose weight.

The gang celebrates Halloween at Stuart's comic book store. Meanwhile, Leonard and Penny discover a new spark in their relationship when he seduces her with science.

Sheldon's friendship with renowned scientist Stephen Hawking is threatened by a game of "Words with Friends," while Penny secretly enrolls in a class at the local college.

Bernadette pressures Howard to move out of his mother's house, while Sheldon finds himself caught in the middle of a fight between Amy and Wil Wheaton.

Howard and Raj try to solve a mystery about Sheldon.

Sheldon and Howard battle over an assigned parking spot.

Howard bonds with his father-n-law on a fishing trip.

Sheldon unwillingly revisits some Christmas memories during a lively game of Dungeons and Dragons, while Raj joins the girls for ladies night out.

Sheldon is accused of sexual harassment at the University and winds up dragging Leonard, Raj and Howard into the fray.

Shane Falco is a football player who believes his dreams have dissipated. Shane regrets believing the NFL would draft him. Fate takes a twist when a strike leaves the fields empty leaving team owners scrambling to fill uniforms.

Our Wipeout teams are THIRSTY. They include a team of PDA-loving first responders and another team begging Jackie Chan to adopt them. Only by completing the toughest Wipeout course in history can their thirst for $25,000 be quenched.

Rachel makes a painful discovery concerning Ross. Monica's new boss gives her an impossible task.

Phoebe learns the surprising truth about her father. Ross makes Monica's Christmas party guests miserable.

Joey gets a great acting opportunity. Rachel dates a guy who is amazingly similar to Ross.

Carol and Susan prepare for their wedding with some help from an uncomfortable Ross.

Ross searches for his former pet monkey. Joey dates an obsessed fan.

Ross spends some quality time with Marcel, his former pet monkey. Chandler gets a big surprise from a sexy former classmate.

Monica's old home video shows Ross' true feelings for Rachel. Joey gives a gaudy gift to Chandler.

Ross and Rachel encounter obstacles to romance. Monica becomes enamored with a handsome, older doctor.

Leonard's car is stolen when the guys take a road trip to a comic book convention in Bakersfield, dressed as Star Trek characters.

Outraged that he's being forced to work with his university nemesis, Barry Kripke (John Ross Bowie), Sheldon faces a crisis of conscience.

When Sheldon and Leonard fight, it affects Penny and Amy's living arrangements. Meanwhile, Raj takes care of Mrs. Wolowitz while Howard is away.

Sheldon struggles to find a Valentine's gift for Amy.

Raj vows never to leave his apartment after a horrible date.

Neighbors in a New England town go to war after one adorns his house with enough Christmas lights to make it visible from space.

Ralphie Parker spends most of his time dodging a bully and dreaming of his ideal Christmas gift, a Red Ryder BB gun. Frequently at odds with his dad but comforted by his mom, Ralphie struggles to make it to Christmas Day with his glasses and hopes intact.

After a tornado whisks Kansas farm girl Dorothy to a magic land, she must travel to the Emerald City for help in getting back home.

Ralphie Parker spends most of his time dodging a bully and dreaming of his ideal Christmas gift, a Red Ryder BB gun. Frequently at odds with his dad but comforted by his mom, Ralphie struggles to make it to Christmas Day with his glasses and hopes intact.

Monica's parents find out about her middle-aged boyfriend. Chandler and Joey argue and it could mean the end of their living arrangement.

Joey wants to move back in with Chandler, but there's a new problem. Phoebe tapes a rock video. Ross upsets Monica.

Monica and Richard experience the same romantic problems as Rachel and Ross. Joey's ill-advised comments to a fan magazine threaten his acting career.

Chandler wants his annoying new roommate to move out. Joey's exorbitant bills come due. The women learn from a book about personal empowerment.

Monica's boyfriend impresses Chandler and Joey. Phoebe finds out what she missed as a child.

Two bullies eject Chandler and Ross from Central Perk. Phoebe meets a brother she never knew she had.

Rachel gets a surprise at her birthday party when her parents show up.

When Phoebe catches chickenpox, her chances for romance with a former lover are almost ruined. Monica worries that she is too strange for Richard.

Rachel is a bridesmaid at her ex-fianc?'s wedding. Monica and Richard's relationship is jeopardized when the subject of children is discussed.

Ross' secret fantasy doesn't stay secret for long after he confides in Rachel. Chandler resumes an old relationship.

Ross becomes frantic trying to get everyone ready to leave to hear his speech at the museum.

After a disastrous blind date, single parents Lauren and Jim agree on only one thing: they never want to see each other again. When they sign up separately for a family vacation, they're stuck sharing a suite at an African safari resort.

After a tornado whisks Kansas farm girl Dorothy to a magic land, she must travel to the Emerald City for help in getting back home.

Leonard, Sheldon and Howard try to advance the cause of women in science by speaking with junior high girls about their future careers, while Raj plans his date with Lucy.

To open or not to open? When Howard finds a letter from his father, he's forced to confront his past. And Leonard and Penny throw a grown-up cocktail party at the apartment.

Leonard, Sheldon and Raj fight for tenure at the University.

After one of his favorite TV shows gets canceled too soon, Sheldon feels lost, so Amy tries to help him get over his compulsive need for closure by retraining his brain.

Leonard and Sheldon hire Professor Proton (Bob Newhart), the host of their favorite childhood TV show to perform. Raj leaves his dog with Howard and Bernadette.

When the girls' trip to Vegas falls through, the guys invite them to a Dungeons & Dragons date night that causes Sheldon and Amy's relationship to take an unexpected turn.

On the sixth season finale, Sheldon and Penny are thrown for a loop when Leonard is offered an exciting new job opportunity overseas.

Leonard is away at sea, so Sheldon and Penny spend time together and spill some revealing secrets. Meanwhile, Howard comes to Raj's aid after his breakup with his girlfriend.

Leonard returns from the North Sea expedition and finds things chilly between him and Sheldon, while Howard's relationship with his mother opens the door to questions about his masculinity.

Raj puts together a scavenger hunt that turns into serious, cutthroat competition among the gang.

An award-winning model and her MMA fighter husband take on the world in tonight's episode. Can they go the distance against a pair of noisy lovers, early retirees and the most fabulous 40-year-olds on the planet?

After a tornado whisks Kansas farm girl Dorothy to a magic land, she must travel to the Emerald City for help in getting back home.

After a disastrous blind date, single parents Lauren and Jim agree on only one thing: they never want to see each other again. When they sign up separately for a family vacation, they're stuck sharing a suite at an African safari resort.

A romantically challenged morning show producer is in for a rude awakening when her bosses team her with a hardcore TV personality who promises to spill the ugly truth on what makes men and women tick.

Sheldon faces his fear of the swimming pool.

Mary plans Pastor Jeff's wedding.

Sheldon catches Paige shoplifting.

George and Georgie go camping with Meemaw's boyfriends.

Sheldon and Georgie bond over a money-making opportunity.

Monica wants to have a baby. A man is stalking Phoebe.

Chandler wants to commit to a relationship with Janice. Phoebe poses as Joey's agent.

Phoebe tries to be more friendly with her half-brother. Ross meets Isabella Rossellini.

The friends recall secrets from their pasts.

Joey sees Janice kissing her husband, whom she is divorcing while she dates Chandler. Rachel's father clashes with Ross.

Chandler and Janice make a difficult decision about their relationship. Monica accidentally injures Ben and tries to hide it from Ross.

On Thanksgiving, a good-natured football game between the friends reveals some serious rivalries.

Rachel wonders if she'll ever get another job after she quits Central Perk. Joey's new job selling Christmas trees upsets Phoebe. Ross breaks a little girl's leg.

Rachel meets a handsome stranger, who might help her career. Chandler gets into trouble with Joey's sisters.

Ross overreacts when Rachel starts working with a handsome guy. Monica becomes enamored with a sexy busboy.

When Monica and Richard accidentally meet, they decide to become friends with dire consequences.

Phoebe's ex-singing partner wants to make Phoebe's signature song, Smelly Cat, a commercial success. Chandler dates a woman with a handicap.

Sheldon is fit to be tied when Amy ruins one of his favorite adventure films, while Leonard finds the key to getting Penny to do his bidding, and Raj and Stuart get creative with their online-dating profiles.

Amy takes a job at Sheldon's university, putting their relationship to the test.

Sheldon makes a major scientific breakthrough, but he feels it may haunt him for the rest of his career. Meanwhile, Howard makes a grand romantic gesture to Bernadette, which causes Penny to put more effort into her relationship with Leonard.

When Sheldon's childhood hero, Professor Proton, seeks Leonard's help with an experiment, the slighted Sheldon goes nuclear and decides to get revenge by befriending another TV science guy.

Leonard fails to stop Sheldon from overreacting after a past slight comes to light, and as punishment Leonard must walk a mile in Sheldon's shoes. Meanwhile, Penny has a run-in with Raj's former girlfriend Lucy.

Howard's mother has a say when he and Bernadette host Thanksgiving dinner for the gang.

When Sheldon's accidental scientific discovery is disproved, Amy and Leonard try to help him deal with the shame and the disappointment. Meanwhile, Howard and Bernadette open their home to Raj for a week.

With Sheldon in Texas, the gang gathers to decorate for Christmas, and they each contemplate if they would have had a wonderful life had they never met him.

Penny turns to Leonard for comfort after her guest appearance on NCIS does not turn out well. She ends up putting Leonard on the spot regarding their relationship. Sheldon works on his sense of humor, and Raj practices talking to girls.

There's impactful news on the work front as Penny makes a big step toward pursuing a full-time acting career, and Sheldon is forced to take a vacation.

Unable to score tickets for Comic-Con, Sheldon decides to stage his own comic-book convention, while the ladies attempt to act like grown ups.

Amy has amour on her mind when she talks Sheldon into a romantic Valentine's Day getaway to Napa Valley wine country. Back at home, Leonard and Penny make an emergency visit to the vet with Raj's dog.

An old man places a hex on Stan, making him age at an alarming rate. Roger and Francine rehearse for a dance competition ... but Roger has something up his sleeve.

Stan panics when Barry comes close to toppling his longstanding wrestling record at Steve's school -- and ends up teaching Roger how to wrestle so he can defeat Barry.

After tricking Roger into going to Iraq, Klaus assumes the role of the Smiths' psychologist, but his emphasis on emotional honesty backfires.

When Steve's new puppy is gravely injured, Stan attempts to save the dog using a doctor who specializes in alternative medicine.

When Hayley experiences kidney failure, Stan and Fran travel into the past to find the man who may be Hayley's real father.

Steve convinces Roger to redeem his most hated and disgusting persona, Ricky Spanish, while Stan and Francine get a visit from the Nigerian boy they once sponsored.

Stan wants Steve to stop playing with toys and be a man, so he brings Steve to Mexico to make love to a prostitute. Roger attempts to retrieve a bottle of wine from Terry and Greg.

Roger opens a crooner's bar in the Smith family's attic and recruits Hayley as his main entertainer. Soon all of Langley Falls becomes enthralled by her singing voice. Stan tries to prove his manhood by negotiating a deal on a car.

The Smith family's vacation turns out to be anything but relaxing when Stan is assigned a mission to kill the activities director at their resort. Hayley and Jeff try to rekindle their romance, while Roger, falls for an older gentleman.

Our Wipeout teams are THIRSTY. They include a team of PDA-loving first responders and another team begging Jackie Chan to adopt them. Only by completing the toughest Wipeout course in history can their thirst for $25,000 be quenched.

An award-winning model and her MMA fighter husband take on the world in tonight's episode. Can they go the distance against a pair of noisy lovers, early retirees and the most fabulous 40-year-olds on the planet?

Meemaw meets Dale's ex-wife.

Sheldon visits CalTech for the very first time.

Sheldon accuses Dr. Sturgis of plagiarism.

George accidentally sends the school librarian to the hospital.

Sheldon sets out to find the perfect neighbors.

Sheldon has a scientific breakthrough at the dentist's office.

Phoebe becomes involved with a foreign diplomat. Ross becomes involved with another woman after a fight with Rachel.

Ross wakes up with Chloe but an oblivious Rachel wants to resume their relationship.

Ross and Rachel remain apart while their friends feel forced to choose between them.

Phoebe is distraught when her brother wants to marry a woman twice his age. While working as a waitress, Monica gets a tip from an admirer worth a small fortune. A hypnosis tape makes Chandler act like a woman.

Ross is upset when Rachel returns his personal belongings and dates Mark. Monica dates a millionaire.

Joey thinks he's found his true love. Rachel's boss dates Chandler, creating big trouble for Rachel. Monica inherits a dollhouse.

When Pete buys a restaurant, Monica must make a difficult decision. Ross makes a sacrifice for Rachel. Joey buys Chandler an unusual pet.

Ross tries to convince Rachel that her date is psychotic. Joey's play gets terrible reviews.

Ross finds a strange growth on his buttocks. Phoebe can't choose between two guys. Monica's boyfriend surprises her.

Monica's boyfriend cannot stop fighting. Chandler's boss is overly friendly.

The friends stay at a beach house. Phoebe meets someone who knows details about her family. Rachel expresses her jealousy of Ross' uninhibited girlfriend.

Ross loves dating Rachel again but hates what he did to accomplish the reconciliation. Phoebe gets to know her mother.

Leonard's purchase of a dining-room table for the apartment doesn't sit well with Sheldon, so much so that it forces him to reevaluate his life. Meanwhile, Bernadette isn't quite over the moon about Howard taking another trip to space.

Things turn rocky between Sheldon and Wolowitz after a barrage of insults, and Bernadette steps in to mediate a peace. Meanwhile, Penny is offered a movie role that may prove embarrassing.

While Sheldon and Howard continue their bonding, Sheldon's visit to see his mommy forces him to start addressing a new reality. The gang are subjected to a murder mystery party that leads them to speculate where they might be in 20 years.

Raj wrestles with dating two women at the same time, Penny is offered a part in a trashy movie, and Sheldon can't decide between two gaming systems.

Raj and Howard double-date, and the latter is flushed with embarrassment after Raj's girlfriend reveals a secret she knows about Howard.

Leonard reinstates Anything Can Happen Thursday, and it leads the regimented Sheldon to attempt something spontaneous, which creates friction among Penny, Amy and Bernadette. Raj requests help from Howard in prepping for a date with Emily.

Sheldon receives counseling from his childhood TV idol, Professor Proton, while Penny and Leonard reach a relationship milestone and turn it into a competition. Also, Bernadette and Amy turn Star Wars Day into a special event for the guys.

A trying day at the movie shoot leaves Penny with questions about her life choices, so she decides to act on it. Caring for a bedridden Mrs. Wolowitz proves a challenge for Howard and Bernadette.

Sheldon gets caught up in all the life-altering changes going on around him and considers a monumental move.

Amy and Leonard take a surprise road trip to Arizona, while Penny goes on a job interview at Bernadette's company, and Howard has problems wrapping his head around Stuart's relationship with Mrs. Wolowitz.

Sheldon is ordered to teach a class, and the gang is surprised when Howard signs up to take it, and tensions between Penny and Bernadette afford Amy an opportunity to play one against the other.

A nervous Wolowitz is thrown for a loop when NASA asks him to toss out the first pitch at a Los Angeles Angels baseball game. Meanwhile, Sheldon brags that he and Amy are a better couple than Leonard and Penny.

Raj's girlfriend, Emily, gives Penny the cold shoulder after he reveals some info about their past history; and the guys contemplate buying into Stuart's comic-book emporium.

Amy and Bernadette accuse former party girl Penny of becoming a party pooper when she lets an email from work impact their girls' weekend in Las Vegas. Meanwhile, the guys brainstorm about inventing something cool.

Our Wipeout teams are THIRSTY. They include a team of PDA-loving first responders and another team begging Jackie Chan to adopt them. Only by completing the toughest Wipeout course in history can their thirst for $25,000 be quenched.

An award-winning model and her MMA fighter husband take on the world in tonight's episode. Can they go the distance against a pair of noisy lovers, early retirees and the most fabulous 40-year-olds on the planet?

Sheldon discovers Mary's been keeping a secret about him.

After graduating high school, Sheldon has a breakdown when he realizes he may not be ready for college. Also, Dale tries to make amends with Meemaw.

While Sheldon volunteers at a local train museum, Missy embarks on a new stage of womanhood, and Georgie discovers his mother's guilty pleasure.

With college in sight, Sheldon is determined to ride his bike without training wheels and has Missy teach him. Meanwhile, Mary and George argue over parenting styles.

Sheldon finds himself in a fierce competition with Paige after their mothers force them to attend Vacation Bible School. Meanwhile, Georgie makes a questionable purchase.

While Mary and George take a trip, Georgie freaks out when his girlfriend thinks she's pregnant. Dale and Meemaw work out their relationship issues with Dungeons and Dragons.

Phoebe thinks her adoptive mother's spirit inhabits a stray cat. Joey's attempt to sell his entertainment center proves hazardous.

Monica tries to prove her mother wrong. Chandler gets into an embarrassing situation while dating Rachel's boss.

Joey makes an odd deal with the building superintendent to prevent him from evicting Rachel and Monica. Phoebe wants to date her sexy massage client.

Joey thinks Chandler hates Joey's new girlfriend -- but the truth could be even more upsetting. Ross and Rachel try to make each other jealous.

Ross' beautiful new girlfriend has a disgusting secret. Chandler becomes more familiar with Joey's girlfriend.

Chandler is guilt-ridden after kissing Joey's girlfriend. Ross' musical talents are not as amazing as he and Phoebe think.

On Thanksgiving, Joey wants to punish Chandler for kissing Kathy. Monica gets a surprise when she visits an eye doctor.

The guys try to be spontaneous and wild. After Monica gives a bad restaurant review, she receives a new career opportunity. Rachel's boss offers her a promotion.

Ross struggles to maintain a long-distance relationship. Chandler tries to get a date for Rachel. Monica schemes to establish authority at her new restaurant job.

Phoebe's half-brother makes an astounding announcement and a thought-provoking request. Joey finds himself in a class struggle.

Phoebe finds out whether she is pregnant or not. A simple challenge escalates into a full-blown contest between the guys and the women.

Rachel schemes to get a handsome client to ask her on a date. Chandler's jealousy causes problems with his girlfriend.

Sheldon and Raj undertake an underground research expedition that turns into a test of how long before they get under each other's skin. Meanwhile, Leonard and Penny argue about money.

Penny's flirtatious sales pitch leaves a doctor-client smitten and the guys must pitch in to help her deal with him, while Bernadette and Amy debate whether female scientists ought to play the sexuality card.

Amy and Bernadette organize a prom to be held atop the guys' apartment complex but Sheldon is leery of all the prom pomp, circumstance and romancing that goes with it.

Leonard needs surgery for a deviated septum, and Sheldon gets his nose out of joint because he feels an operation is too dangerous and that his roommate may not make it out alive.

It's a banner day for Sheldon as he bids a sad farewell to his Fun With Flags podcast. Meanwhile, Leonard, Howard and Raj probe a late professor's research in search of some hidden significance.

On Christmas Eve, Amy plans a traditional Victorian dinner, while Raj, Leonard and Howard scramble to remove a pigeon that flew into the clean room at the university.

While Raj eagerly awaits data from a space probe in which he was involved, Howard keeps distracting him. Later, dress shopping with Penny and Amy doesn't exactly prove to be a good fit for Leonard and Sheldon.

Sheldon becomes concerned that his cushy lifestyle is impacting his professional progress and keeping him from achieving scientific renown, so he asks the gang to make life more difficult for him.

Our Wipeout teams are THIRSTY. They include a team of PDA-loving first responders and another team begging Jackie Chan to adopt them. Only by completing the toughest Wipeout course in history can their thirst for $25,000 be quenched.

An award-winning model and her MMA fighter husband take on the world in tonight's episode. Can they go the distance against a pair of noisy lovers, early retirees and the most fabulous 40-year-olds on the planet?

While college orientation does not go as Sheldon planned, Mary is mistaken for a university student and invited to a party.

Sheldon's first day of college is derailed by his new philosophy teacher. Also, Mary and Brenda live vicariously through Missy's first day of middle school.

Meemaw takes matters into her own hands when Sheldon's philosophy teacher, Professor Ericson, sends him into a tailspin.

Sheldon and his dad dine with President Hagemeyer and a university benefactor. Also, Dale and his ex-wife invite Meemaw to their son's wedding.

Dr. Linkletter pushes Sheldon to make friends with his fellow students, and Georgie gets a pager.

Sheldon, Dr. Linkletter and Meemaw team up on a science experiment. Also, Mary is jealous that Pastor Jeff and Brenda are spending so much time together.

Charlton Heston finds Joey in a compromising position during a movie shoot. Rachel regrets asking Ross for a favor.

Chandler's annoying former girlfriend reappears. Ross plays rugby to impress Emily with painful results.

Trying to become better acquainted with her sexy client, Rachel inadvertently thwarts Ross' plans for a romantic evening with his girlfriend.

Monica helps Ross tell his girlfriend that he loves her. Phoebe gets some surprising news about her pregnancy.

Ross and his ex-wife become jealous when their lovers go to England together. Rachel's plans to seduce her boyfriend go awry.

Drastic changes occur in Ross' relationship with Emily. Monica and Rachel will do anything to get their old apartment back from the guys.

Rachel reacts drastically to Ross' engagement. Chandler becomes exasperated by Joey's snoring.

Rachel and the engaged Ross reminisce separately about when they dated each other. The friends get invitations to Ross' wedding but not all of them are going.

Joey loses Ross' treasured wedding ring. Phoebe has extreme mood variations from her pregnancy.

Rachel stays home while the others go to England for Ross' wedding.

Rachel frantically tries to get to London before Ross marries Emily. Ross' father clashes with Emily's.

Will Emily forgive Ross before their honeymoon? Monica and Chandler agree to end their new relationship.

An online troll rips Leonard and Sheldon's published physics paper, so the guys rally to defend the two and expose the bully, while a girls night out leads to Penny, Amy and Bernadette dishing about embarrassing past events.

Amid the excitement of Stuart reopening his comic-book store, Howard gets some unsettling news; and after teaching Sheldon how to "let it go," Penny doesn't practice what she preaches when she learns something maddening about Amy.

An experiment designed to make participants fall in love piques Penny and Leonard's interest, so they decide to put it to the test. Meanwhile, Leonard, Amy, Raj and Emily have an encounter with a "zombie."

There's trouble in paradise when Amy discovers Sheldon signed up for a one-way mission to colonize Mars, and the two get into a dogfight at a pet store. Meanwhile, Leonard makes a very "adult" purchase for Penny.

An electrical short thaws the last meal that was cooked by Mrs. Wolowitz, and the gang ponders what to do with it, while Sheldon and Leonard's work is featured in a magazine, but only one receives credit.

A speaking engagement at UC Berkeley puts Leonard and Sheldon in a galaxy not too far, far away from their idol George Lucas' Skywalker Ranch, and they considrer dropping by.

Penny hosts a Halloween party, putting Leonard, Sheldon, Wolowitz and Koothrappali through a new test of their social skills.

When Leonard is offered a trip to Switzerland on Valentine's Day to see a particle accelerator, he must choose between taking Penny or Sheldon.

The guys go to a garage sale and find a ring from the Lord of the Rings films, and the rare find threatens their friendship.

Sheldon and Leonard get invited to a housewarming party at Wil Wheaton's house. Howard gets an out-of-this-world opportunity!

Leonard reinstates Anything Can Happen Thursday, and it leads the regimented Sheldon to attempt something spontaneous, which creates friction among Penny, Amy and Bernadette. Raj requests help from Howard in prepping for a date with Emily.

In the Season 8 finale, Leonard and Penny are pressured to set a wedding date by Sheldon, whose relationship with Amy has taken an interesting turn.

Sheldon and Amy try to eliminate stress from wedding planning by applying math to the process. Raj "breaks up" with Howard after realizing his best friend is actually hurting his confidence.

In the Season 11 finale, when Amy's parents and Sheldon's family arrive for the wedding, everybody is focused on making sure all goes according to plan -- everyone except the bride and groom.

Our Wipeout teams are THIRSTY. They include a team of PDA-loving first responders and another team begging Jackie Chan to adopt them. Only by completing the toughest Wipeout course in history can their thirst for $25,000 be quenched.

An award-winning model and her MMA fighter husband take on the world in tonight's episode. Can they go the distance against a pair of noisy lovers, early retirees and the most fabulous 40-year-olds on the planet?

Sheldon campaigns to become Dr. Linkletter's lab assistant. Meanwhile, Georgie enlists the help of Mr. Lundy, the drama teacher, for a surprising business venture.

Sheldon refuses to ride in a car after getting into an accident with Meemaw. Meanwhile, Meemaw is forced to take the church shuttle while her car is in the shop.

When the IRS accuses Sheldon of making a mistake, he stops at nothing to prove them wrong. Then, when Dale is forced to get a colonoscopy, he tries to convince Meemaw to join him.

Sheldon faces extreme consequences after installing a pirated computer game. Meanwhile, Mary and Meemaw take Brenda out for Girls Night, while George watches Billy.

Sheldon finds himself at odds with Paige once again when she considers enrolling at East Texas Tech. Meanwhile, Mary seeks the advice of June when looking for a change.

The Coopers discuss the possibilities of black holes and alternate universes when Dr. Sturgis comes over for dinner.

Ross' new wife won't speak to him. Rachel appoints Monica her advisor in romance. Phoebe feels neglected.

While Phoebe delivers triplets, Joey experiences his own pain. Monica plans a date with a male nurse to spite Chandler.

Joey challenges Phoebe to perform a completely selfless act. Monica gets upset when Chandler gloats about sex. Ross might finally reconcile with Emily but he must make a tough decision.

Ross tells Rachel that he cannot be around her once Emily comes to New York. Chandler and Monica try to have a romantic weekend.

Will Ross obey Emily and move away from his friends? Monica and Rachel meet a monster.

Joey and Chandler regret letting Ross move in with them. Rachel schemes to get her new neighbor to ask her on a date.

The friends find out about Monica's worst Thanksgiving ever.

Joey becomes exasperated from hiding Chandler and Monica's secret. Ross gets in trouble when he expresses his rage.

A bored Ross creates havoc in Joey and Chandler's lives. Rachel is disturbed by her date's inappropriate relationship with his sister.

On New Year's Eve, the friends make resolutions for the coming year but keeping them proves difficult.

Chandler's behavior toward his boss annoys Monica. Ross' latest romance astounds everyone.

Phoebe meets another long-lost relative. Joey wears a shoulder bag.

When Sheldon and Amy build a fort, they come to a crossroad in their relationship. Wolowitz is shocked when a man claiming to be his half-brother shows up. When Penny is invited to be on Wil's podcast, she and Leonard have an argument.

In the event of alien contact, NASA asks Raj to craft a message for the extraterrestrials, and the guys battle over how it should be handled. Meanwhile, Penny must decide between auditioning for a film role or keeping her job in pharmaceutical sales.

Wolowitz questions his abilities when he and Sheldon can't get a drone to fly. A canceled flight nearly prevents Leonard from giving the commencement address. Raj pits his parents against each other when his father cuts him off financially.

Leonard and Sheldon's mothers come to town to celebrate their sons getting an award, but the opinionated women engage in an altercation over religion.

In the Season 8 finale, Leonard and Penny are pressured to set a wedding date by Sheldon, whose relationship with Amy has taken an interesting turn.

Season 9 premiere, Penny has a problem dealing with Leonard's confession about having kissed another woman, while Sheldon is confused about Amy calling a timeout on their relationship.

To ease Penny's mind, Leonard pays a visit to the woman he kissed during his expedition to the North Sea, while Sheldon's breakup with Amy leads him to retaliate by shooting a special episode of "Fun with Flags".

The guys surprise Leonard with a belated bachelor-party weekend in Mexico, but their plans hit a bump in the road when they get a flat tire on the way. Meanwhile, the girls lean on Penny to tell her family that she and Leonard eloped.

Two terminally ill men leave their hospital ward and set out to complete a list of things they want to do before they die.

Our Wipeout teams are THIRSTY. They include a team of PDA-loving first responders and another team begging Jackie Chan to adopt them. Only by completing the toughest Wipeout course in history can their thirst for $25,000 be quenched.

An award-winning model and her MMA fighter husband take on the world in tonight's episode. Can they go the distance against a pair of noisy lovers, early retirees and the most fabulous 40-year-olds on the planet?

Chandler and Monica's relationship becomes less of a secret. Ross must prove to his boss that he's sane in order to return to work.

Chandler thinks Monica wants more from their relationship. Ross fails to impress his new neighbors.

Joey wonders if he is in love with Monica. Phoebe impersonates a police officer.

Rachel interviews for a great job but she may get it for the wrong reason. Monica competes to have a better relationship than Phoebe's.

The Grinch is irritated at the thought of the nearby village having a happy time celebrating Christmas. So, disguised as Santa Claus -- with his dog Max made to look like a reindeer -- he raids the village to steal all the Christmas things.

Rachel submits to peer pressure at work. Joey and Ross' son audition for the same commercial but only one can get the part.

Ross' flirting technique fails to impress a cute pizza-delivery woman. A surprise awaits Joey when he tells everyone about his big television appearance.

The guys enjoy riding along with a police officer until a gunshot is heard. Rachel overhears a telephone message for Ross from his second ex-wife.

Phoebe's boyfriend wants her to move in with him. Ross and Joey involve Chandler and Monica in an obsessive game.

Based on a true story, a group of steroid-abusing bodybuilders engage in a campaign of kidnapping, extortion and murder in Florida.