Raj: You're not going to prison.
Leonard: But, boy, it is funny to think about.

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.

Penny: Hey, since when do you do laundry on a Thursday?
Sheldon: Oh, I had an accident at work, I slipped and fell on my soup sack.
Penny: You know, there was a time I would say "What's a soup sack?" But I'm glad we're past that.

Penny: You know, there was a time I would say "God bless you," and then you would say "If you must invoke an imaginary deity, how about Thor?" And I would say, "How do you know I didn't mean Thor?" And then you would say "Touche," and that there ends the tale of why I no longer say "God bless you."
Sheldon: Well, we have had some fun, haven't we?
Penny: Oh, yeah.

Stuart: Oh, thanks again for letting me use your laptop last night.
Bernadette: No problem.
Stuart: Was just doing my taxes.
Bernadette: Okay.
Stuart: Actually, if I could if I could just check one more-
Bernadette: Already cleared the browser history.
Stuart: You're a good woman.