Leonard: How do you feel about children?
Penny: Um, they're okay, I guess. I mean, if I saw one, I wouldn't throw a rock at it.
Leonard: Why would you throw a rock at a child?
Penny: (chuckles) I just said I wouldn't.

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?

Leonard: If I take it off, Sheldon wins.
Penny: Sweetie, every night you don't kill him in his sleep, he wins.

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

Amy: Hey. Wait a minute, what about us? I mean, we're married now. Maybe we want to buy the house next door.
Sheldon: Well, Amy, we can't move. I'd have to change all the tags in my underwear.
Amy: You can buy new ones.
Sheldon: New house, new underwear. What am I, in the Witness Protection Program?

Sheldon: You're awfully quiet.
Leonard: Sorry.
Sheldon: No, I like it.
Leonard: Got a lot on my mind.
Sheldon: Would you like to talk about it?
Leonard: Not really.
Sheldon: Grape Nuts for breakfast, quiet car ride, things are really breaking my way today.

Amy: What the hell, Penny?!
Penny: I'm gonna need more than that.
Amy: You're not having kids? How could you do this to me?
Penny: How is it any of your business?
Amy: Because your kids were supposed to be friends with my kids. Who's gonna be friends with them now?
Penny: They will find other friends.
Amy: Oh, sure, 'cause Sheldon's DNA plus my DNA equals a kid who knows how to make friends. Grow up!