Sheldon: He wrote back! "Cooper and Hofstadter resorting to juvenile attempts at humor is proof they have nothing to back up their ridiculous paper. It should come as no surprise given they work at Cal-Tech, essentially a technical school where even the physicists are basically engineers".
Oh, engineers. Do you know how insulting that is?
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.

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.

Sheldon: Can I respond now?
Leonard: Do it.
Sheldon: You mess with the bull, you get the horns. I'm about to show this guy just how horny I can be.
Leonard: Somebody else do it.

Sheldon: I like it. I think you're on to something.
Leonard: Really? You're not messing with me?
Sheldon: Not at all. In fact, I have got something for just such an occasion. I was starting to think I'd never get a chance to give it to you. Good job!
Leonard: You're giving me a sticker?
Sheldon: Not just a sticker. That's a sticker of a kitty saying "Mee-wow".
Leonard: I'm not a preschooler.
Sheldon: Fine, I'll take it back.
Leonard: I earned this. Back off.

Bernadette: (In pageant video) And you should pick me for Miss. California Quiznos 1999, because I want to tell you what I want, what I really really want. I'll tell you what I want, what I really really want. I wanna. I wanna. I wanna. I wanna, really, really, be the California Quiznos 1999.