Raj: Well, so you're on his side?
Penny: I'm just saying, that's what friends do. You know, they bust on each other. It doesn't mean anything.
Leonard: Well, I'm not surprised you think so.
Penny: Why is that?
Leonard: Well, you can be kind of mean to me.
Penny: Well, that's because you're- Wow. I don't know how to finish that sentence, either.

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: I mean, it's not that I think we're living in sin, but I do like the idea that our next act of intimacy will be a legal requirement.

Amy: Maybe we should just get married at City Hall and forget about everything else.
Sheldon: City Hall, hmm. I do like metal detectors and the sound of permits being denied.

Sheldon: Neither of them will be the actual cake. I'm just using it as a bargaining chip to get Amy to agree to the whole wedding party getting rings and us getting one ring to rule them all.
Howard: I forget, which mental hospital are you guys registered at?