Raj: But y-you blocked your number, right?
Howard: Relax, this is not my first creepy phone call. It's like riding a bike ... slowly past a girl's house.

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

Wil Wheaton: All right, Professor Proton fans, get ready to meet Dr. Sheldon Cooper and Dr. Amy Farrah Fowler, a pair of real-life scientists who may win the Nobel Prize. That's like the Kids' Choice Award, but with more science and less slime.

Sheldon: Kids' Choice Award? Why would they let kids choose anything? They're basically human larvae.
Wil Wheaton: Well, they are kind of our target audience.
Sheldon: Greetings, children. Toys, am I right?
Amy: He is. He has hundreds of them.

Amy: Okay, imagine you're looking in a mirror. The image you see looks just like you. That's called symmetrical.
Sheldon: Now imagine you have a billion mirrors, and each of them reflects one thing about you correctly and a billion things about you incorrectly. And imagine the set of incorrect things are floating in an abstract n-dimensional hyperspace. Now imagine there was never a mirror to begin with.