Wolowitz: That's more like we're a tall thin woman who wants to make a coat out of your Dalmatians.

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: So you can never take it (the sweater) off?
Leonard: No.
Raj: Not even to sleep?
Leonard: No.
Howard: So you're just an idiot?
Leonard: It's called proving a point.
Howard: Is the point you're an idiot?

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: Teams are traditionally named after fierce creatures thus intimidating one's opponent.
Raj: Then we could be the Bengal tigers.
Sheldon: Poor choice. You know, gram for gram no animal exceeds the relative fighting strength of the army ant.
Raj: Maybe so, but you can't incinerate a Bengal tiger with a magnifying glass.

Raj: I say we wait until he looks at us then laugh, like "Yes, you're a smart and strong competitor but we're also smart and strong and we have a reasonable chance of defeating you".

Howard: Don't you think I should answer the engineering questions? I am an engineer.
Sheldon: By that logic I should answer all the anthropology questions because I'm a mammal.