Howard: Don't come in, Ma.
Mrs. Wolowitz: Why not?
Leslie: He's got company.
Howard: Oh, there's the arrhythmia.
Mrs. Wolowitz: Is she Jewish?
Howard: Are you Jewish?
Leslie: No.
Howard: Yes!

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.

Bernadette: Maybe we should get one of those machines to help her up the stairs.
Howard: You mean a forklift?

Sheldon: Sheldon Cooper does not cry.
Howard: That's true, you'd rust.

Howard: [looking at his caller ID] Ooh, looks like I'm gonna have sex tonight. [answering phone] Hey, baby...
Penny: His right hand is calling him?

Penny: What are we gonna do?
Leonard: We? No, no, no. You had your chance to be "we" for like a year and a half now. Right now, you are you and you are screwed!

Leslie: Boy, your heart's racing. I must've really gotten you going.
Wolowitz: Well, it's partly you, partly my transient idiopathic arrhythmia.
Leslie: Sexy.