Penny: Well you wouldn't have asked me either.
Leonard: I would have asked you. In my head. On the way home. While I was having a good cry.

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Leonard: My point is, while you're spending all this time on your own, building computers or practicing your cello, what you're really doing is becoming interesting. When people finally do notice you, they're gonna find someone a lot cooler than they thought. And for those of you that were popular in high school, it's over, sorry. Thank you. Congratulations.

Leonard: [to a "smiling" Sheldon] We're here to see Koothrappali, not kill Batman.

Sheldon: I really did think you looked pretty.
Amy: You did?
Sheldon: Yes. So much so that I started to panic.
Amy: Well you can relax. Just because you think I look pretty doesn't mean we have to spend the night together.
Sheldon: Were you hoping we would because it's prom?
Amy: I'm always hoping. But tonight, I just wanted to have a nice time with you. Maybe dance with someone who has arms.

Stuart: Oh, so she's good enough for Howard but not for me?
Howard: Yeah.
Bernadette: Yeah. Go have weird relationships with your own mother and cousin. This is his turf.

Raj: Okay, here we go. [to Leonard & Penny] Say cheese. [to Sheldon & Amy] Say cheese. [to Howard & Bernadette] Say cousin.