Leonard: A long time ago, I made a deal with Howard involving you.
Penny: Okay, I don't know where this is going, but tread carefully, because this may be the last conversation we ever have.

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

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

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

Bernadette: Does your mother call you every day at work to see if you had a healthy lunch?
Howard: My mother calls me every day at work to see if I had a healthy bowel movement.

Wil Wheaton: Game over, Moonpie.

Wil Wheaton: Did that guy just say "Revenge is a dish best served cold" to me in Klingon?