Penny: Hey, how was your lecture?
Leonard: Oh, it was so good. I-I-I mean, it-it started great, and then the, the middle was great, and then the ending was like [imitates explosion]. So great.
Penny: Leonard, if you went to House of Pies again, just say it.
Leonard: [stammers] Wait, if you think I'm lying, why do you think I'm eating pies? Why don't you think I'm having an affair?
Penny: Listen, i-it's fine, just next time, bring me a slice.

Sheldon: Woman, you are playing with forces beyond your ken.
Penny: Yeah, well your Ken can kiss my Barbie.

Raj: [to Amy] If you were having Sheldon's baby, would you really want him in the room?
Penny: Yeah, if he's in the room when they're making the baby, I'll give you $10.

Penny: I mean, who even reads Scientific American?
Leonard: It's kind of a big deal.
Penny: If it's such a big deal, how come the biggest celebrity they could get for the cover is a molecule?

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.