Leonard: Besides, can you even name one romantic thing you've done for me?
Penny: I can name tons.
Leonard: And sex doesn't count.
Penny: Oh.

Penny: At one point, they had me figure out how to get a banana out of a puzzle box.
Leonard: Wait, Sheldon gave me a banana in a box. He was testing me, too.
Penny: Unbelievable.
Leonard: And how could a chimp even solve that? That was impossible.
Penny: Really? You couldn't get it out?

Leonard: If I take it off, Sheldon wins.
Penny: Sweetie, every night you don't kill him in his sleep, he wins.

Sheldon: Woman, you are playing with forces beyond your ken.
Penny: Yeah, well your Ken can kiss my Barbie.

Sheldon: Sheldon Cooper does not get lucky.
Amy: You and me both, brother.

Bernadette: Great news. A raccoon virus just crossed the species barrier and can now infect humans.
Raj: Why is that great news?
Bernadette: In the pharmaceutical business we have a saying: mo' infections, mo' money.

Howard: So I'm almost done writing the song for Bernadette. Are you cool playing the cello?
Leonard: If by cool you mean willing to, yes. If by cool you mean cool, clearly you've never seen me play the cello.