"The White Asparagus Triangulation"

Sheldon tries to secure Leonard's relationship with Stephanie and sets up a scenario where Leonard can prove he's the alpha male.

"The Lizard-Spock Expansion"

Wolowitz thinks he's found his soul mate, Dr. Stephanie Barnett (Sara Rue), until she meets Leonard. Wolowitz lets Stephanie drive the Mars rover, which gets stuck in a ditch.

"The Panty Piñata Polarization"

When Penny's cable goes out, she starts going over the guys' apartment to watch America's Next Top Model. However, after violating some of Sheldon's arbitrary rules, he bands her from coming over.

"The Cooper-Nowitzki Theorem"

After an open house night at the University with grad students, an obsessive student Ramona Nowitzki (Riki Lindhome) likes Sheldon and makes her way into becoming his girlfriend / assistant.

"The Euclid Alternative"

When Leonard needs to work the graveyard timeslot to gain access to the lasers for his experiment, Sheldon loses his ride to the university.

"The Griffin Equivalency"

Raj is included in People's "30 under 30 to watch" list, prompting the rest of the group to be jealous.

"The Barbarian Sublimation"

When Penny locks herself out of the apartment, she comes to hang out with Sheldon in his as he plays Age of Conan. Penny, frustrated by her recent failures in life soon plays and becomes addicted to Conan.

"The Codpiece Topology"

The guys return from the Renaissance fair and see Penny has already moved on to a new guy, Eric (Travis Schuldt), prompting Leonard to pursue a relationship with prior fling Leslie Winkle.

"The Bad Fish Paradigm"

Penny and Leonard return from their date from the end of season one and Leonard finds Howard and Raj spying on them via webcam.

"The Tangerine Factor"

Penny breaks up with her boyfriend after he posted intimate details about her on his blog. Leonard tries to comfort her but accidentally sends her back into the arms of her boyfriend.

TBBT Quotes

Penny: Here's a question-- as an alien pretending to be human, are you planning to engage in any post-prom mating rituals with Amy?
Sheldon: There are post-prom mating rituals?
Penny: Not always. Unless your date drives a van with an air mattress, then always.
Sheldon: Well, if it's part of the prom experience, then I'm open to it.
Penny: You're kidding.
Sheldon: I may be an alien, but I have urges.If Amy wants to copulate by firing her eggs into space, well, then, I will happily catch them with the reproductive sac on my upper flermin. I'm not the best at reading facial cues, but I can see that you're a little turned on.

Leonard: Hi. I'm Leonard. You are beautiful. You pop, sparkle and buzz electric. I'm going to pick you up at eight, show you a night you will never forget.
Raj: Where are we going?