Amy: Should you really be sitting in Sheldon's spot?
Raj: He's in Texas, he'll never know.
Penny: Wouldn't be so sure about that.
Leonard: Yeah, he has a very sensitive butt. Look, it's true. Once I saw him sit on a bunch of loose change and add it up.

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

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: You don't go into science for the money.
Bernadette: Speak for yourself. Last month my company both invented and cured restless eye syndrome. Ka-ching, ya blinky chumps!

Raj: It's too late. He's been murdered by someone in this room. Welcome to another classic Koothrappali murder mystery dinner.
Amy: I'm leaving.

Sheldon: Well then why are you doing it?
Mary: Because I'm not perfect, Shelly. And that man's booty is.