Howard: Wow. I wonder what that guy could've done to make Sheldon not talk to him for 20 years.
Leonard: I wonder if it'd work a second time.

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.

Amy: I tried to ask him about it, and he invoked section three, article five of the marriage contract: beeswax, none of your.

Bernadette: Look, I think that's LeBron over there.
Penny: James?
Bernadette: No, LeBron Kershenbaum.

Amy: Hey, did you guys know that Sheldon had a best friend growing up named Tam?
Leonard: Was that the imaginary talking koala?
Amy: No. He's a real person who apparently betrayed him.
Leonard: Yeah, so did the koala.