Wil Wheaton: Hey, Leonard, I have an opening in my D&D game next week, and I was wondering if you were interested in playing.
Leonard: Well, yes, thank you.
Wil Wheaton: Okay, great. Now, here's the thing, you can't tell anyone. I'm serious, not Howard, not Raj, and certainly not Sheldon.
Leonard: Okay.
Wil Wheaton: I'm really sorry to put you in a position where you have to lie to your friends-
Leonard: See you there!

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

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.