- 1 The Bad Fish Paradigm
Penny's first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.
Average Episode Rating: 4.2 | Air Date: 2008-09-22
- 2 The Codpiece Topology
A jealous Leonard reacts to Penny's new guy by rebounding with Leslie.
Average Episode Rating: 4.5 | Air Date: 2008-09-29
- 3 The Barbarian Sublimation
Sheldon creates a monster when he introduces Penny to online gaming.
Average Episode Rating: 4.5 | Air Date: 2008-10-06
- 4 The Griffin Equivalency
Raj gets an inflated ego and makes a play for Penny after being referenced in a magazine article.
Average Episode Rating: 4.3 | Air Date: 2008-10-13
- 5 The Euclid Alternative
Leonard and his friends stage an intervention to force Sheldon to face his fear of driving.
Average Episode Rating: 4.6 | Air Date: 2008-10-20
- 6 The Cooper-Nowitzki Theorem
Sheldon and the gang are confused when a young grad student is attracted to him.
Average Episode Rating: 4.8 | Air Date: 2008-11-03
- 7 The Panty Piñata Polarization
When Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate.
Average Episode Rating: 4.4 | Air Date: 2008-11-10
- 8 The Lizard-Spock Expansion
Leonard inadvertently steals away the new woman Wolowitz thinks is the love of his life.
Average Episode Rating: 4.0 | Air Date: 2008-11-17
- 9 The White Asparagus Triangulation
Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon's stringent standards.
Average Episode Rating: 4.3 | Air Date: 2008-11-24
- 10 The Vartabedian Conundrum
Leonard asks Penny for advice when his new relationship starts moving too fast.
Average Episode Rating: 3.6 | Air Date: 2008-12-08
- 11 The Bath Item Gift Hypothesis
Penny starts dating Leonard's handsome colleague; Leonard and his friends are tortured by Sheldon's obsession with gift-giving etiquette.
Average Episode Rating: 4.4 | Air Date: 2008-12-15
- 12 The Killer Robot Instability
Penny's criticism of Wolowitz's romantic life pushes him into depression and AWOL for a fighting robot battle the rest of guys are depending on him for.
Average Episode Rating: 4.0 | Air Date: 2009-01-12
- 13 The Friendship Algorithm
Sheldon creates a scientific procedure for making friends.
Average Episode Rating: 4.0 | Air Date: 2009-01-19
- 14 The Financial Permeability
Sheldon's solution to Penny's financial difficulty leads to a confrontation between Leonard and Penny's ex-boyfriend.
Average Episode Rating: 3.7 | Air Date: 2009-02-02
- 15 The Maternal Capacitance
Leonard and Penny are drawn together after a disastrous visit from Leonard's mother.
Average Episode Rating: 4.3 | Air Date: 2009-02-09
- 16 The Cushion Saturation
A paintball game leads to a fight between Sheldon and Penny, and romance for Leslie and Wolowitz.
Average Episode Rating: 4.2 | Air Date: 2009-03-02
- 17 The Terminator Decoupling
Leonard, Sheldon and Wolowitz are ecstatic to learn that a famous science-fiction actress (Summer Glau) is on board the train they are taking to San Francisco.
Average Episode Rating: 4.3 | Air Date: 2009-03-09
- 18 The Work Song Nanocluster
Penny's home business turns into a complete nightmare when Sheldon takes over.
Average Episode Rating: 4.1 | Air Date: 2009-03-16
- 19 The Dead Hooker Juxtaposition
Penny squares off with a new beautiful female neighbor who may become the building's "new Penny."
Average Episode Rating: 4.1 | Air Date: 2009-03-30
- 20 The Hofstadter Isotope
A fellow comic book enthusiast's hitting on Penny leads to Leonard and Howard going to a bar's Ladies' Night.
Average Episode Rating: 4.0 | Air Date: 2009-04-13
- 21 The Vegas Renormalization
Leonard and Koothrappali escort a heartbroken Wolowitz to Las Vegas, and Sheldon becomes locked out of his apartment and must stay with Penny.
Average Episode Rating: 4.1 | Air Date: 2009-04-27
- 22 The Classified Materials Turbulence
Penny's second date with Stuart sees her making a comment that gives Leonard new hope for a relationship with her. Wolowitz realizes there's a crucial error in a NASA project he's working on.
Average Episode Rating: 4.4 | Air Date: 2009-05-04
- 23 The Monopolar Expedition
The guys' plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leonard.
Average Episode Rating: 4.1 | Air Date: 2009-05-11
- 24 DVD Extra - Physicist To The Stars
- 25 DVD Extra - Testing The Infinite Hilarity Hypothesis In Relation To The Big Bang Theory
- 26 DVD Extra - Gag Reel