Penny: And what kind of doctor removes shoes from asses?

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

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

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

Sheldon: Oh gravity, thou art a heartless bitch.

Sheldon: I have a masters and two PhDs. I should not have to do this.

Penny: Yes, I know men can't fly.
Sheldon: No, no let's assume that they can. Lois Lane is falling, accelerating at an initial rate of 32ft per second, per second. Superman swoops down to save her by reaching out two arms of steel. Ms. Lane, who is now traveling at approximately 120 miles per hour, hits them, and is immediately sliced into three equal pieces.
Leonard: Unless Superman matches her speed and decelerates.
Sheldon: In what space, sir, in what space? She's two feet above the ground. Frankly, if he really loved her, he'd let her hit the pavement. It would be a more merciful death.