Raj: So Ruchi and I decided to keep things casual.
Penny: (scoffs)
Raj: What? What? I can handle casual.
Penny: (scoffs)
Raj: Oh, why do you keep doing that with your face?
Penny: Because you keep saying stupid things with yours.

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.

Sheldon: They're very different. Physics answers the question: what is the nature of the universe? Geology answers the question: you know, what'd I just trip over?

Sheldon: I've been modeling different types of dark matter and the traces they would leave on the zircon inside your meteorite.
Bert: What's this one here?
Sheldon: That's actually a dark matter model of my own creation. I call it the Cooper Boson.
Bert: Cool. I got to name a rock once. I named it Moderately Sedimented Shale. Guess I kind of pooped the bed on that one.

Amy: What's going on?
Sheldon: What if there was something I wanted to do, but I was worried other people would think less of me?
Amy: Is that other person me, and does it happen in the bedroom, in which case I think I'm cool with it?
Sheldon: No. It's about working with Bert on - You know what? I'm not even gonna say it. I am just gonna say the letter it starts with and -"ology". G-- Oh, no, that's not gonna work.