Penny: Okay, look, we don't need to rush into anything. All right? Maybe instead of Leonard moving in with me, we just leave things the way they are, and sometimes we'll sleep over there, and sometimes we'll sleep over here.
Sheldon: But mostly here?
Penny: Sure.

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

Raj: [to Amy] If you were having Sheldon's baby, would you really want him in the room?
Penny: Yeah, if he's in the room when they're making the baby, I'll give you $10.

Penny: I mean, who even reads Scientific American?
Leonard: It's kind of a big deal.
Penny: If it's such a big deal, how come the biggest celebrity they could get for the cover is a molecule?

Howard: You know what's really happening here? Your girlfriend is breaking up our band.
Raj: She has nothing to do with this. I am my own man.
Howard: Oh, please. Your brain belongs to whoever's willing to sleep with you.
Raj: That is so not true.
Howard: Really? Remember when you were gonna get circumcised for Rachel Bernstein?
Raj: That had nothing to do with Rachel. It was an overreaction to a bad zipper injury.

Howard: What kind of music are you thinking of?
Stuart: I like all kinds of music, but my favorite genre is free.

Howard: I don't need this. I'm quitting the band!
Raj: Fine, I quit, too!
Howard: Then get out of my house!
Raj: With pleasure!
*door slams*
*Howard sighs*
Howard: Raj, wait!
Raj: What took you so long?