Penny: Um, I'm free tonight.
Leonard: Are you saying you want to get married?
Penny: Vegas isn't that far away.
Leonard: I'm in. Let's do it.

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: 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.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Leonard: What am I supposed to do?
Penny: Err, keep your mouth off other women.

Penny: Wait, what is wrong with you two? He was talking about television during their date night.
Sheldon: Oh, not just date night. Our 5th anniversary.
Penny: Okay, see, that's even dumber than you wondering if being bitten by a goat would give you the powers of a goat.
Sheldon: If that happens, don't make me wait ten years to watch you eat a tin can.

Sheldon: Amy's mad at me, and I'm not clear why.
Penny: Okay, were you talking before she got upset?
Sheldon: Yes.
Penny: That's probably it.