Penny: You know, she's my mother-in-law. Why can't I bond with her like that?
Bernadette: Amy's with Sheldon, who she loves like a son. You're with her son, who she doesn't.

Bernadette: Gosh, Amy. I'm sensing a little hostility. Is it maybe because like Sheldon's work, your sex life is also theoretical?

Bernadette: (Shouting from the bathroom) How many times do I have to tell you to replace the toilet paper when it's empty?
Howard: I'm in the middle of something.
Bernadette: So am I!

Leonard: You don't go into science for the money.
Bernadette: Speak for yourself. Last month my company both invented and cured restless eye syndrome. Ka-ching, ya blinky chumps!

Stuart: Anyone else need anything before I go?
Howard: I'll give you a dollar if you make fun of Raj.
Stuart: That's mean.
Howard: Five.
Stuart: You look like Tigger if Tigger looked like a jackass.
Howard: Uh, if you ever need a reference or anything, just let me know.

Penny: Helium.
Sheldon: Yes.
Penny: Yes.
Sheldon: Taylor Swift.
Penny: Yes. Pi.
Sheldon: Yes. Kardashian.
Penny: More specific.
Sheldon: Khloe?
Penny: Yes.
Sheldon: See, I remembered because if it looks like Kim it's Kim, if it looks kind of like Kim it's Kourtney, and if it looks nothing like Kim it's Khloe.

Penny: Oh, that's a Venn Diagram, and I remember because I thought to myself, "Venn is he gonna stop talking about this diagram?"