Penny: No, no, you guys do your experiments. I'll go pick up dinner.
Leonard: Are you sure?
Penny: Yeah, you're having science fun, and I don't want to interfere, or watch you.

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.

Howard: (singing) Alone in my temple in the middle of Peru, A giant stone ball with nothing to do,
Raj: But if you steal my idol, I will roll right over you
All: Cause I'm six tons of granite, And micaceous schist. Yeah, I'm six tons of granite, And micaceous schist,
Bert: I'm gonna crush you, I'm gonna mush you, You took my idol, I'm homicidal, Gonna roll over you till your brains come out, And your bones will crunch and your blood will spout! I'm not just a rock, baby. I'm a boulder.
All: Cause I'm six tons of granite, And micaceous schist. Yeah, I'm six tons of granite, And micaceous schist, Yeah, I'm six tons of granite-

Howard: What up, my Hebrews and She-brews?!

Leonard: Thought you were getting us dinner.
Penny: Sorry. I had to stop at Sheldon's and help him solve string theory.
Amy: What?
Penny: Yeah, turns out the answer's knots.
Leonard: That's cute, but you can't have knots in more than four dimensions.
Penny: Mmm ... you can if you consider them sheets. [chuckling] Good night.