Penny: You know what? I'm just gonna take the bus to work.
Leonard: Penny, I can still drive you.
Penny: Oh, no, no, it's okay. You might slip on a banana peel and get me pregnant.

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: Are you planning on kidnapping a woman?
Sheldon: Sarcasm?
Howard: Yes, but mixed with genuine concern.

Howard: I have a two-part question.
Sheldon: Go ahead.
Howard: A: Are you kidding? And B: Seriously, are you freaking kidding me?
Sheldon: A: I rarely kid, and B: when I do kid, you will know it by my use of the word "Bazinga".
Howard: So you're saying the two of you are going to be sleeping in the same bed?
Sheldon: Yes. Bazinga.

Sheldon: Now listen, one of the great minds of the 21st century is about to play host to one of the other great minds of the 21st century. So pay attention. Years from now, my biographer might ask you about this event.
Leonard: Oh, I have so many things to tell your biographer.