Sheldon: No, I have the feeling that she's hiding something.
Leonard: I wouldn't worry about it. She's probably just distracted by work.
Sheldon: Well, whatever it is, it's troubling me. I can't eat, I can't sleep. And don't even ask about the consistency of my bowel movements.
Howard: You heard him, guys, don't ask.

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.

Howard: I invented a game. Want to play?
Leonard: Sure.
Howard: It's called Emily or Cinnamon. I give you actual quotes I've heard Raj say, and you guess if he was talking to his girlfriend or his dog.

Bernadette: Does your mother call you every day at work to see if you had a healthy lunch?
Howard: My mother calls me every day at work to see if I had a healthy bowel movement.

Leonard: Superman's gone. My stormtrooper's gone.
Sheldon: Your Klingon word-of-the-day calendar's gone.
Leonard: I'd say "damn it" in Klingon, but that wasn't until next month.
Sheldon: It's "khoo-vakh".
Leonard: Khoo-vakh!

Sheldon: Oh, I don't mind, I'm very good at complaining. If it were an Olympic sport, I'd complain about what a stupid sport it is and then I'd take home the gold.

Leonard: Sheldon, this is not a big deal. It's a little white lie, everyone does it.
Raj: Not me, I'm a 100% honest in all of my relationships.
Howard: And how single are you right now?
Raj: Eating-cake-on-the-toilet single.