Leonard: What about if you went out with me?
Penny: Are you asking me out?
Leonard: Um, yes, I am, asking you out.
Penny: Wow.
Leonard: I was just going off your comment about the nice guy...
Penny: No, I know, I got that. Yeah, totally.
Leonard: ...thing and honestly, it's no big deal.
Penny: Yes.
Leonard: Yes what?
Penny: Yes, I will go out with you.
Leonard: Really?
Penny: Yeah. Why not, I mean, what do I have to lose?
Leonard: Yeah. That's the spirit.

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, I'm really glad you decided to learn Mandarin.
Sheldon: Why?
Howard: Once you're fluent, you'll have a billion more people to annoy instead of me.

Howard: So you're saying, if in the depths of despair she throws herself at you and demands you take her right there, right now, you'll just walk away?
Leonard: I said I'm her friend, not her gay friend.

Leonard: Before you say anything, have you heard of Schrodinger's cat?
Penny: Actually, I've heard far too much about Schrodinger's cat.
Leonard: Good.
*Leonard and Penny kiss*
Penny: All right, the cat's alive. Let's go to dinner.