Mrs. Wolowitz:What's going on? Are you boys rough housing?
Howard: We're just talking, Ma!
Mrs. Wolowitz: If you don't settle down right now, I'm not gonna let you have any more sleepovers.
Howard: For God's Sake, Ma, I'm 27 years old. And it's not even a school night.

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.

Sheldon: I wouldn't tell you the secret. Sssh!
Leonard: What secret? Tell me the secret.
Sheldon: Mom smokes in the car. Jesus is okay with it, but we can't tell dad.
Leonard: Not that secret, the other secret.
Sheldon: I'm Batman! Ssssh!

Penny: Sheldon, could I ask you a question?
Sheldon: I would prefer that you not, but I wouldn't go so far as to forbid it.

Leonard: How could you just sit there and let them spy on me?
Sheldon: They were very smart. They used my complete lack of interest in what you are doing.