Good Guy Fluctuation
Season 5, Ep. 7
An attractive comic book artist tests Leonard and Priya's relationship; Sheldon tries to scare his friends.
The Rhinitis Revelation
Season 5, Ep. 6
Sheldon finds himself competing with the gang for his mother's attention when she visits.View Gallery ►
The Wiggly Finger Catalyst
Season 5, Ep. 4
Raj meets a woman with whom he's able to talk.
The Pulled Groin Extrapolation
Season 5, Ep. 3
Amy and Leonard try to become better acquainted; Bernadette, Howard and Mrs. Wolowitz spend the weekend together.
The Skank Reflex Analysis *Premiere*
Season 5, Ep. 1
Penny hits a low point when she realizes what she's done by sleeping with Raj; Sheldon becomes the leader of the paintball team.
The Roommate Transmogrification
Season 4, Ep. 24
Hearing Star Trek sex games between Leonard and Priya sends Raj to live with Sheldon. Bernadette's earning her Ph.D makes the guys mock Wolowitz for not having one even more.View Gallery ►
The Engagement Reaction
Season 4, Ep. 23
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.
The Wildebeest Implementation
Season 4, Ep. 22
Amy recognizes a dinner invitation to be a chance for Bernadette to spy on Leonard and Priya for Penny. Meanwhile, a lonely Raj considers taking experimental medication to cure himself of his inability to talk to women while sober, and Sheldon devises three-person chess.View Gallery ►
The Agreement Dissection
Season 4, Ep. 21
Miffed over Priya breaking down the Roommate Agreement using legal theory, Sheldon joins Penny, Bernadette, and Amy on their girls' night.View Gallery ►
The Herb Garden Germination
Season 4, Ep. 20
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.
The Zarnecki Incursion
Season 4, Ep. 19
When Sheldon has his World of Warcraft account hacked and his character stolen from, the guys team up to discover out who did it. Meanwhile, Bernadette and Amy try to help Penny deal with Leonard's continuing relationship with Priya.View Gallery ►
The Prestidigitation Approximation
Season 4, Ep. 18
Sheldon is baffled by Wolowitz's magic trick. Meanwhile, Priya disapproves of Leonard continuing to be friends with Penny.View Gallery ►
The Toast Derivation
Season 4, Ep. 17
Told Leonard is the center of the gang and miffed that they've started hanging out at Raj's, Sheldon seeks to form a new group of friends of which he can be the center.View Gallery ►
The Cohabitation Formulation
Season 4, Ep. 16
Bernadette tells Howard that it's time to choose between moving in with her or staying with his mother. Leonard discovers Raj's sister Priya is back in town and reconnects with her, and Amy tries to comfort Penny when she finds out.View Gallery ►
The Benefactor Factor
Season 3, Ep. 15
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.
The Thespian Catalyst
Season 4, Ep. 14
Hoping it will make him a better teacher, Sheldon has Penny give him acting lessons. Raj has fantasies about Bernadette.View Gallery ►
The Love Car Displacement
Season 4, Ep. 13
A science convention at a hotel leads to Bernadette running into an ex-boyfriend and Wolowitz worrying he can't quite compare.View Gallery ►
The Bus Pants Utilization
Season 4, Ep. 12
Their friendship becomes strained when Sheldon tries to take over Leonard's creation of a smartphone application that solves differential equations.
The Justice League Recombination
Season 4, Ep. 11
The guys get Zack and Penny to join their Justice League costume for a New Year's Eve bash at the comic book store.View Gallery ►
The Alien Parasite Hypothesis
Season 4, Ep. 10
Amy crushes on one of Penny's dim ex-boyfriends, Zack. Raj and Wolowitz argue over who'd be the better superhero.View Gallery ►
The Boyfriend Complexity
Season 4, Ep. 9
When Penny's father visits, she gets Leonard to pretend to still be her boyfriend. Meanwhile, Howard, Raj, and Bernadette spend the night on an astronomy project.View Gallery ►
The 21-Second Excitation
Season 4, Ep. 8
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.
The Apology Insufficiency
Season 4, Ep. 7
The rest of the gang is interviewed by the FBI for Wolowitz's security clearance, with Sheldon accidentally letting slip some damaging information.View Gallery ►
The Irish Pub Formulation
Season 4, Ep. 6
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.
The Desperation Emanation
Season 4, Ep. 5
Leonard is depressed to realize all the other guys have girlfriends, while he doesn't. Amy wants to introduce Sheldon to her mother.View Gallery ►