Howard: Why would the military want Sheldon?
Leonard: I don't know. Target practice?

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.

Leonard: Penny. We are made of particles that have existed since the moment the universe began. I like to think those atoms traveled fourteen billion years through time and space to create us, so that we could be together and make each other whole.

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

Barry Kripke: Whoa, whoa, whoa. You didn't tell me we were doing this just to stick it to Sheldon.
Leonard: Well-
Barry Kripke: I messing with you. This sundae just got a cherry on top!

Leonard: Hey, is Sheldon working on our project again?
Colonel Williams: Did he say that?
Leonard: No, he wouldn't tell us.
Colonel Williams: Huh. So he can keep his mouth shut. How do I get him to do that?

Sheldon: And worse than that, Edison filmed the first on-screen kiss, so he's basically a pornographer. Although every time I put that in Wikipedia, someone takes it out.