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: My point is, while you're spending all this time on your own, building computers or practicing your cello, what you're really doing is becoming interesting. When people finally do notice you, they're gonna find someone a lot cooler than they thought. And for those of you that were popular in high school, it's over, sorry. Thank you. Congratulations.

Leonard: [to a "smiling" Sheldon] We're here to see Koothrappali, not kill Batman.

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.

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!

Penny: I thought they fired you guys.
Sheldon: They did, but then they hired me back.
Leonard: Well, you better not be working on our project, because we're a team.
Sheldon: Leonard, there is no "I" in team. However, there is an "I" in "I'm working with the military and you're not." There's five of them, in fact.