Raj: You know a man can care deeply about a woman and a pet. It's not strange.
Leonard: Ooh, Emily. I heard him say that to Emily.

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.

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

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.

Howard: I invented a game. Want to play?
Leonard: Sure.
Howard: It's called Emily or Cinnamon. I give you actual quotes I've heard Raj say, and you guess if he was talking to his girlfriend or his dog.

Leonard: At least listen to it through headphones. I'm trying to sleep, good night.
Sheldon: Boy. Taylor was right. Haters gonna hate, hate, hate, hate, hate.

Amy: Look, your anxiety levels are right in the zone.
Sheldon: Really? Oh, that's fantastic. No wait, they're dropping. Why are they dropping?
Amy: Because you're happy they're elevated.
Sheldon: Oh, that is infuriating. Oh look, they're going back up again. Terrific. Oh no, they're going back down.