8.2/104,998 votes#1 - The Bad Fish Paradigm
Season 2 Episode 1 - Aired 9/22/2008
Penny's first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.
Director: Mark Cendrowski
Writer: N/A
8.0/104,609 votes#2 - The Codpiece Topology
Season 2 Episode 2 - Aired 9/29/2008
A jealous Leonard reacts to Penny's new guy by rebounding with Leslie.
Director: Mark Cendrowski
Writer: N/A
8.7/105,361 votes#3 - The Barbarian Sublimation
Season 2 Episode 3 - Aired 10/6/2008
Sheldon creates a monster when he introduces Penny to online gaming.
Director: Mark Cendrowski
Writer: N/A
7.9/104,652 votes#4 - The Griffin Equivalency
Season 2 Episode 4 - Aired 10/13/2008
Raj gets an inflated ego and makes a play for Penny after being referenced in a magazine article.
Director: Mark Cendrowski
Writer: N/A
8.3/104,769 votes#5 - The Euclid Alternative
Season 2 Episode 5 - Aired 10/20/2008
Leonard and his friends stage an intervention to force Sheldon to face his fear of driving.
Director: Mark Cendrowski
Writer: N/A
8.2/104,793 votes#6 - The Cooper-Nowitzki Theorem
Season 2 Episode 6 - Aired 11/3/2008
Sheldon and the gang are confused when a young grad student is attracted to him.
Director: Mark Cendrowski
Writer: N/A
8.6/105,060 votes#7 - The Panty Piñata Polarization
Season 2 Episode 7 - Aired 11/10/2008
When Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate.
Director: Mark Cendrowski
Writer: N/A
8.0/104,561 votes#8 - The Lizard-Spock Expansion
Season 2 Episode 8 - Aired 11/17/2008
Leonard inadvertently steals away the new woman Wolowitz thinks is the love of his life.
Director: Mark Cendrowski
Writer: N/A
8.1/104,518 votes#9 - The White Asparagus Triangulation
Season 2 Episode 9 - Aired 11/24/2008
Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon's stringent standards.
Director: Mark Cendrowski
Writer: N/A
7.6/104,431 votes#10 - The Vartabedian Conundrum
Season 2 Episode 10 - Aired 12/8/2008
Leonard asks Penny for advice when his new relationship starts moving too fast.
Director: Mark Cendrowski
Writer: N/A
9.1/107,394 votes#11 - The Bath Item Gift Hypothesis
Season 2 Episode 11 - Aired 12/15/2008
Penny starts dating Leonard's handsome colleague; Leonard and his friends are tortured by Sheldon's obsession with gift-giving etiquette.
Director: Mark Cendrowski
Writer: N/A
7.8/104,465 votes#12 - The Killer Robot Instability
Season 2 Episode 12 - Aired 1/12/2009
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.
Director: Mark Cendrowski
Writer: N/A
7.9/104,435 votes#13 - The Friendship Algorithm
Season 2 Episode 13 - Aired 1/19/2009
Sheldon creates a scientific procedure for making friends.
Director: Mark Cendrowski
Writer: N/A
8.0/104,393 votes#14 - The Financial Permeability
Season 2 Episode 14 - Aired 2/2/2009
Sheldon's solution to Penny's financial difficulty leads to a confrontation between Leonard and Penny's ex-boyfriend.
Director: Mark Cendrowski
Writer: N/A
8.8/105,282 votes#15 - The Maternal Capacitance
Season 2 Episode 15 - Aired 2/9/2009
Leonard and Penny are drawn together after a disastrous visit from Leonard's mother.
Director: Mark Cendrowski
Writer: N/A
8.1/104,408 votes#16 - The Cushion Saturation
Season 2 Episode 16 - Aired 3/2/2009
A paintball game leads to a fight between Sheldon and Penny, and romance for Leslie and Wolowitz.
Director: Mark Cendrowski
Writer: N/A
8.0/104,764 votes#17 - The Terminator Decoupling
Season 2 Episode 17 - Aired 3/9/2009
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.
Director: Mark Cendrowski
Writer: N/A
8.1/104,435 votes#18 - The Work Song Nanocluster
Season 2 Episode 18 - Aired 3/16/2009
Penny's home business turns into a complete nightmare when Sheldon takes over.
Director: Peter Chakos
Writer: N/A
8.1/104,473 votes#19 - The Dead Hooker Juxtaposition
Season 2 Episode 19 - Aired 3/30/2009
Penny squares off with a new beautiful female neighbor who may become the building's "new Penny."
Director: Mark Cendrowski
Writer: Steven Molaro
7.9/104,295 votes#20 - The Hofstadter Isotope
Season 2 Episode 20 - Aired 4/13/2009
A fellow comic book enthusiast's hitting on Penny leads to Leonard and Howard going to a bar's Ladies' Night.
Director: Mark Cendrowski
Writer: David Goetsch
8.5/104,637 votes#21 - The Vegas Renormalization
Season 2 Episode 21 - Aired 4/27/2009
Leonard and Koothrappali escort a heartbroken Wolowitz to Las Vegas, and Sheldon becomes locked out of his apartment and must stay with Penny.
Director: Mark Cendrowski
Writer: N/A
8.1/104,248 votes#22 - The Classified Materials Turbulence
Season 2 Episode 22 - Aired 5/4/2009
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.
Director: Mark Cendrowski
Writer: N/A
8.2/104,378 votes#23 - The Monopolar Expedition
Season 2 Episode 23 - Aired 5/11/2009
The guys' plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leonard.
Director: Mark Cendrowski
Writer: Eric Kaplan, Richard A. Rosenstock
The Best Episodes of The Big Bang Theory Season 2
Every episode of The Big Bang Theory Season 2 ranked from best to worst. Discover the Best Episodes of The Big Bang Theory Season 2!
Physicists Leonard and Sheldon find their nerd-centric social circle with pals Howard and Raj expanding when aspiring actress Penny moves in next door.
Genre:Comedy
Network:CBS
Season 2 Ratings Summary
"The Bad Fish Paradigm" is the best rated episode of "The Big Bang Theory" season 2. It scored 8.2/10 based on 4998 votes. Directed by Mark Cendrowski and written by N/A, it aired on 9/22/2008. This episode is rated 0.2 points higher than the second-best, "The Codpiece Topology".