Bernadette: More coffee?
Penny: No, Leonard's taking me to a physics lecture, and coffee'll just keep me awake.

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

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?

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

Bernadette: Gosh, Amy. I'm sensing a little hostility. Is it maybe because like Sheldon's work, your sex life is also theoretical?

Howard: Are you listening to yourself?
Sheldon: I always listen to myself. It's one of the great joys of my life.

Sheldon: You know what they say. Revenge is a dish best served nude.