The Bad Fish Paradigm
Season 2, Episode 1 TV-14
CC
HD
CC
SD
In the second season premiere, after her first date with Leonard goes awry, Penny finds an unwilling confidant in Leonard's anti-social roommate, Sheldon.
The Codpiece Topology
Season 2, Episode 2 TV-14
CC
HD
CC
SD
Penny and Leonard compete to see who will be the first to move on after their breakup. When Leonard sees Penny with a handsome new guy (guest star TRAVIS SCHULDT Scrubs), he enters into a rebound relationship with Sheldon's nemesis, Leslie Winkle (series regular SARA GILBERT).
The Barbarian Sublimation
Season 2, Episode 3 TV-14
CC
HD
CC
SD
Sheldon creates a monster when he introduces Penny to the world of online gaming. Especially when her addiction wreaks havoc on his life.
The Griffin Equivalency
Season 2, Episode 4 TV-14
CC
HD
CC
SD
Raj's ego puts all of his friendships in jeopardy when he gets an inflated sense of self. Newly famous because of an article in a magazine, Raj (series regular KUNAL NAYYAR) makes a disastrous play for Leonards longtime crush, Penny.
The Euclid Alternative
Season 2, Episode 5 TV-14
CC
HD
CC
SD
Leonard and his friends stage an intervention to make Sheldon confront his longstanding fear of driving.
The Cooper-Nowitzki Theorem
Season 2, Episode 6 TV-14
CC
HD
CC
SD
A young grad student’s attraction to Sheldon confuses everyone – including Sheldon himself.
The Panty Pinata Polarization
Season 2, Episode 7 TV-14
CC
HD
CC
SD
Sheldon and Penny engage in a battle of wills as Penny vows to get revenge on Sheldon when he bans her from the apartment for a series of petty infractions.
The Lizard-Spock Expansion
Season 2, Episode 8 TV-14
CC
HD
CC
SD
Wolowitz (series regular SIMON HELBERG) thinks he's found the love of his life (guest star SARA RUE) until she meets Leonard.
The White Asparagus Triangulation
Season 2, Episode 9 TV-14
CC
HD
CC
SD
Sheldon can barely contain his joy when Leonard starts dating a woman (SARA RUE) who meets Sheldon's exacting standards.
The Vartabedian Conundrum
Season 2, Episode 10 TV-14
CC
HD
CC
SD
Leonard just can't say no. When his relationship with new girlfriend, Stephanie starts moving too fast, Leonard turns to Penny for advice.
The Bath Item Gift Hypothesis
Season 2, Episode 11 TV-14
CC
HD
CC
SD
Leonards handsome colleague starts dating Penny. And Leonard's friends are being tormented by Sheldon's obsession with gift-giving etiquette.
The Killer Robot Instability
Season 2, Episode 12 TV-14
CC
HD
CC
SD
When Pennys comment about Wolowitzs love life sends him into a depressed stupor, his friends lose their most important teammate in an upcoming fighting robot competition.
The Friendship Algorithm
Season 2, Episode 13 TV-14
CC
HD
CC
SD
Socially awkward Sheldon develops a scientific procedure for making friends.
The Financial Permeability
Season 2, Episode 14 TV-14
CC
HD
CC
SD
Sheldon's "simple" solution to Penny's financial problem leads to a confrontation between Leonard and Penny's hulking ex-boyfriend, Kurt (guest star BRIAN PATRICK WADE).
The Maternal Capacitance
Season 2, Episode 15 TV-14
CC
HD
CC
SD
A disastrous visit from Mrs. Hofstadter (special guest star CHRISTINE BARANSKI) brings Leonard and Penny closer together.
The Cushion Saturation
Season 2, Episode 16 TV-14
CC
HD
CC
SD
A paintball game has surprising consequences for Leonard and his friends when it leads to a fight between Penny and Sheldon – and romance for Wolowitz and Leslie.
The Terminator Decoupling
Season 2, Episode 17 TV-14
CC
HD
CC
SD
A train trip to San Francisco takes a major detour when Leonard, Sheldon, Wolowitz and Raj discover that beautiful sci-fi actress SUMMER GLAU ("Terminator") is onboard.
The Work Song Nanocluster
Season 2, Episode 18 TV-14
CC
HD
CC
SD
Penny’s home hair products business becomes a complete nightmare when a caffeine-addled Sheldon takes over.
The Dead Hooker Juxtaposition
Season 2, Episode 19 TV-14
CC
HD
CC
SD
There’s a new queen bee in the building! Penny develops a rivalry with a sexy female neighbor who moves into the building and threatens to become the “new Penny.”
The Hofstadter Isotope
Season 2, Episode 20 TV-14
CC
HD
CC
SD
While Stuart (guest star KEVIN SUSSMAN), a fellow comic book-loving pal of the guys, romances Penny, Leonard and Wolowitz venture out into the world of "Ladies' Night" at a local bar.
The Vegas Renormalization
Season 2, Episode 21 TV-14
CC
HD
CC
SD
Leonard and Koothrappali take a heartbroken Wolowitz to Las Vegas, leaving Sheldon locked out of his apartment and forced to bunk with Penny.
The Classified Materials Turbulence
Season 2, Episode 22 TV-14
CC
HD
CC
SD
Things begin to look up for Leonard when Penny makes a surprising revelation on her second date with Stuart (guest star KEVIN SUSSMAN). Meanwhile, Wolowitz enlists his friends' help when he discovers a critical design flaw in his project for NASA.
The Monopolar Expedition
Season 2, Episode 23 TV-14
CC
HD
CC
SD
On the second season finale, Leonard and Penny reconsider their feelings for one another. When Leonard and his friends decide to spend the summer working – at the North Pole – Penny is conflicted.