Penny: No, I've been reading Bernadette's parenting book. It's like the answer key to the Sheldon test.

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

Leonard: What am I supposed to do?
Penny: Err, keep your mouth off other women.

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

Leonard: It's fine, I've been driving him for years. What's one more day?
Sheldon: Oh, and I've got a new car game we can play. It's called "What siren am I?"

Sheldon: All right, you ready for your next one? Just a warning, this one's a little annoying. (imitates a high-pitched siren)
Leonard: Let's take a little little break, I'm getting a headache.
Sheldon: Aw, right in the middle of our fun game.
Leonard: Yeah, weird.

Raj: This is great, the two of us hanging out. Why didn't we think of this earlier?
Sheldon: Agreed. I don't need Amy to watch a movie. I can not hold your hand just as easily.
(Sheldon starts the movie)
Sheldon: In the book this is based on, that man's the killer.