Penny: So, what ya doing? Better not be building a robot girlfriend.
Leonard: No. Although Howard was making some real strides in that area until he met Bernadette.
Penny: You're kidding.
Leonard: Nope. Now the Lisatronic 3000 just sits in a box waiting for the phone to ring.

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?

Stuart: Hey. Hey, look at you guys!
Amy: I'm Raggedy Ann, and he's Raggedy C-3PO.
Sheldon: It was a compromise. I lost.

Howard: A week ago, I was an astronaut.
Bernadette: Yeah, well, today you're a Smurf! Keep moving!

Howard: Okay, here it is. Bernadette said you guys are all sick of me talking about my trip to space. Is that true?
Sheldon: Yes.
Raj: No.
Sheldon: We seem to have different approaches here. I was going for helpful honesty. I have no idea what you're doing.
Raj: It's called being nice.
Sheldon: Okay. If you think being nice will get him to shut up, I'll try it.