Howard: I can't believe we have to ask Sheldon to come back and help us.
Leonard: Oh, boo-hoo. I spent four grand on a gift that only got rid of him for an afternoon.

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, 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.

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

Howard: How'd you even get that up the stairs?
Sheldon: I said to myself, "I think I can, I think I can." And then I couldn't, so I paid two men who promised not to come rob us later.

Colonel Williams: What's this?
Leonard: Oh, nothing. Just some math we don't need.
Colonel Williams: This is a different approach. Are you trying to get the guidance system even smaller?
Leonard: It's just a theory. Uh, it's not even worked out.
Colonel Williams: Oh. I want this.
Howard: But we've already met the agreed upon specs. Going smaller would require weeks' worth of new computations.
Colonel Williams: So get the kid with the two shirts to do it.

Leonard: You know, I do have a way to get him out of our hair. I've been holding onto this for a few years, but maybe now's the time.
Howard: We can just lock the door; you don't have to kill him.
Leonard: You can't kill him; he'll just respawn at the last save point.