The BEST episodes of The Big Bang Theory season 4
Every episode of The Big Bang Theory season 4, ranked from best to worst by thousands of votes from fans of the show. The best episodes of The Big Bang Theory season 4!
A woman who moves into an apartment across the hall from two brilliant but socially awkward physicists shows them how little they know about life outside of the laboratory.
#1 - The Roommate Transmogrification
Season 4 - Episode 24 - Aired 5/19/2011
When Bernadette receives her PhD, Wolowitz feels emasculated. Raj and Leonard swap apartments and Penny does something she regrets.
#2 - The Prestidigitation Approximation
Season 4 - Episode 18 - Aired 3/10/2011
Sheldon is baffled by Wolowitz's magic trick. Meanwhile, Leonard realizes dating Priya may make it impossible to continue being friends with Penny.
#3 - The Herb Garden Germination
Season 4 - Episode 20 - Aired 4/7/2011
Sheldon and Amy decide to start several rumors about the others as a test. Meanwhile, Howard takes his relationship with Bernadette to an even higher level.
#4 - The Justice League Recombination
Season 4 - Episode 11 - Aired 12/16/2010
The guys find a "super" use for Penny's new boyfriend, Zack, when they enter a costume contest as the Justice League.
#5 - The Boyfriend Complexity
Season 4 - Episode 9 - Aired 11/18/2010
Penny asks Leonard to lie to her father, while Howard, Raj and Bernadette pull an all-nighter at a telescope.
#6 - The Engagement Reaction
Season 4 - Episode 23 - Aired 5/12/2011
When Howard finally breaks the news to his mom that he's engaged to Bernadette, it lands her in the hospital.
#7 - The Agreement Dissection
Season 4 - Episode 21 - Aired 4/28/2011
When Priya finds a loophole in the roommate agreement to throw Sheldon out for the night, Penny, Amy and Bernadette take him to a nightclub.
#8 - The Zarnecki Incursion
Season 4 - Episode 19 - Aired 3/31/2011
The guys go all out to help Sheldon find the person responsible for hacking his online gaming account, while the girls' hatred for Priya increases.
#9 - The Robotic Manipulation
Season 4 - Episode 1 - Aired 9/23/2010
Penny tags along on Sheldon's first ever date; Wolowitz finds a new use for a robotic arm.
#10 - The Love Car Displacement
Season 4 - Episode 13 - Aired 1/20/2011
When the gang road trips to a conference, tensions run high when Bernadette runs into her ex-boyfriend.
#11 - The Toast Derivation
Season 4 - Episode 17 - Aired 2/24/2011
Sheldon becomes concerned when everybody begins to hang out at Raj's apartment and discovers Leonard is the center of the group.
#12 - The Cruciferous Vegetable Amplification
Season 4 - Episode 2 - Aired 9/30/2010
Realizing he will not live long enough to download his consciousness into a robot body, Sheldon tries to extend his life span.
#13 - The Benefactor Factor
Season 4 - Episode 15 - Aired 2/10/2011
A wealthy donor to the university makes Leonard consider how far he's willing to go for the sake of science.
#14 - The 21-Second Excitation
Season 4 - Episode 8 - Aired 11/11/2010
While the guys camp in line for a long-awaited movie screening, Penny and Bernadette invite Amy to her first slumber party.
#15 - The Cohabitation Formulation
Season 4 - Episode 16 - Aired 2/17/2011
As Wolowitz contemplates taking things with Bernadette to the next level, Leonard rekindles his relationship with Raj's sister Priya.
#16 - The Irish Pub Formulation
Season 4 - Episode 6 - Aired 10/28/2010
Leonard keeps a romantic affair a secret from Sheldon, Howard and Raj.
#17 - The Wildebeest Implementation
Season 4 - Episode 22 - Aired 5/5/2011
Raj attempts to cure his social anxiety disorder while Penny uses Bernadette to spy on Leonard and his girlfriend.
#18 - The Apology Insufficiency
Season 4 - Episode 7 - Aired 11/4/2010
Sheldon's answers during an FBI interview put Wolowitz's security clearance in jeopardy.
#19 - The Zazzy Substitution
Season 4 - Episode 3 - Aired 10/7/2010
The guys are concerned as Sheldon searches for an alternative to human companionship.
#20 - The Hot Troll Deviation
Season 4 - Episode 4 - Aired 10/14/2010
An embarrassing secret of Wolowitz's comes to light, while Sheldon and Raj have a small war at work.
#21 - The Desperation Emanation
Season 4 - Episode 5 - Aired 10/21/2010
Leonard realizes he’s the only one without a girlfriend, while Sheldon wants to get rid of his.
#22 - The Thespian Catalyst
Season 4 - Episode 14 - Aired 2/3/2011
Hoping it will make him a better teacher, Sheldon has Penny give him acting lessons. Raj has fantasies about a friend's girlfriend.
#23 - The Alien Parasite Hypothesis
Season 4 - Episode 10 - Aired 12/9/2010
Amy finds she has sexual feelings for Penny's ex, while Koothrappali and Wolowitz try to prove who would be the better superhero.
#24 - The Bus Pants Utilization
Season 4 - Episode 12 - Aired 1/6/2011
Leonard's idea for a smartphone app derails his friendship with Sheldon.
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