Leonard: Hang on, if you're making all this money, where is it?
Penny: In a safe place.
Leonard: What does that mean, under your bed?
Penny: No, it means a diversified portfolio of stocks and bonds. I'm not overly conservative. I'm young, so my guy said I can afford to take some risks.
Leonard: Wait a minute, you have "a guy"?
Penny: Don't you have a guy?
Leonard: Why would I have a guy?! I don't have any money!

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?

Sheldon: It reminds me of when my stupid brother and sister would build forts in the living room, and wouldn't let me in. I hated that so much.
Amy: You know, there's nothing I can do about getting you invited to the symposium, but if you wanted we could build a fort.
Sheldon: Isn't that a little juvenile?
Amy: More juvenile than this? *Puts up picture of smiling Sheldon to her face*

Josh: So, I have to ask, was the robot sexy?
Howard: It was actually just a mechanical hand.
Josh: 'Cause that's all you need, right?
Howard: You are my brother.

Leonard: Well, you can spend the rest of the day being bitter about this--
Sheldon: Agreed.
Leonard: I was going to say "or," but why bother?