Series 3 Episode 20
Sheldon tries to hide his friendship with Penny from Leonard but it isn't long before his double life is exposed. Can he remain friends with both Penny and Leonard?
Series 3 Episode 1
The Electric Can Opener Fluctuation: Sheldon heads to Texas after learning that his friends meddled with his expedition data
Series 3 Episode 1
Series 3 Episode 2
The Jiminy Conjecture: Leonard and Penny feel awkward around each other after their romantic liaison
Series 3 Episode 2
Series 3 Episode 3
The Gothowitz Deviation: Sheldon tries to modify Penny's behaviour using chocolate
Series 3 Episode 3
Series 3 Episode 4
The Pirate Solution: Raj reluctantly accepts a job offer from Sheldon so that he won't be sent back to India
Series 3 Episode 4
Series 3 Episode 5
The Creepy Candy Coating Corollary: Sheldon enters a competition that pits him against his nemesis, Wil Wheaton from Star Trek
Series 3 Episode 5
Series 3 Episode 6
The Cornhusker Vortex: Sheldon teaches Leonard about football so that he can fit in with Penny's friends
Series 3 Episode 6
Series 3 Episode 7
The Guitarist Amplification: Sheldon is upset when Leonard and Penny argue about Penny's male friend staying over
Series 3 Episode 7
Series 3 Episode 8
The Adhesive Duck Deficiency: Sheldon has to come to Penny's rescue after she dislocates her shoulder in the shower
Series 3 Episode 8
Series 3 Episode 9
The Vengeance Formulation: Howard is scared about committing to Bernadette, so he avoids her
Series 3 Episode 9
Series 3 Episode 10
The Gorilla Experiment: Howard and Penny are jealous when Bernadette is fascinated with Leonard's physics project
Series 3 Episode 10
Series 3 Episode 11
The Maternal Congruence: Leonard's hurt when his mum arrives unannounced and then learns Sheldon knew of the visit
Series 3 Episode 11
Series 3 Episode 12
The Psychic Vortex: A rift forms between Leonard and Penny when he ridicules her belief in psychics
Series 3 Episode 12
Series 3 Episode 13
The Bozeman Reaction: The gang work on creating a state-of-the-art security system after the flat is burgled
Series 3 Episode 13
Series 3 Episode 14
The Einstein Approximation: Sheldon gets a job at the Cheesecake Factory to kick-start his creativity
Series 3 Episode 14
Series 3 Episode 15
The Large Hadron Collision: Sheldon's jealous when Leonard asks Penny to visit the Large Hadron Collider with him
Series 3 Episode 15
Series 3 Episode 16
The Excelsior Acquisition: Sheldon misses a chance to meet Stan Lee when he's summoned to court for a driving offence
Series 3 Episode 16
Series 3 Episode 17
The Precious Fragmentation: The gang squabble over a ring that they believe was used in The Lord of the Rings movies
Series 3 Episode 17
Series 3 Episode 18
The Pants Alternative: Sheldon earns an award but is scared of making a speech at the ceremony to receive it
Series 3 Episode 18
Series 3 Episode 19
The Wheaton Recurrence: Leonard tells Penny that he loves her but doesn't get the response he hoped for
Series 3 Episode 19
Series 3 Episode 20
The Spaghetti Catalyst: Sheldon tries to hide his friendship with Penny from Leonard
Series 3 Episode 20