Leonard: You really didn't think I'd notice my stuff was missing?
Penny: Uh, did you notice your key chain?
*Leonard goes to the door and checks his keys*
Leonard: Where's Batman?!

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: Oh, I don't mind, I'm very good at complaining. If it were an Olympic sport, I'd complain about what a stupid sport it is and then I'd take home the gold.

Leonard: Superman's gone. My stormtrooper's gone.
Sheldon: Your Klingon word-of-the-day calendar's gone.
Leonard: I'd say "damn it" in Klingon, but that wasn't until next month.
Sheldon: It's "khoo-vakh".
Leonard: Khoo-vakh!

Leonard: Sheldon, this is not a big deal. It's a little white lie, everyone does it.
Raj: Not me, I'm a 100% honest in all of my relationships.
Howard: And how single are you right now?
Raj: Eating-cake-on-the-toilet single.