Penny: God, what is wrong with me.
Leonard: Nothing, you're perfect.
Penny: Gah, I'm not perfect.
Leonard: Yes you are.
Penny: You really think so, don't you? [kisses Leonard]
Leonard: Penny?
Penny: Yeah.
Leonard: How much have you had to drink tonight?
Penny: Just…. a lot.
Leonard: Are you sure that your being drunk, and your being angry with Kurt doesn't have something to do with what's going on here?
Penny: It might. Boy, you're really smart.
Leonard: Yeah, I'm a frickin' genius.

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.

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: My point is, while you're spending all this time on your own, building computers or practicing your cello, what you're really doing is becoming interesting. When people finally do notice you, they're gonna find someone a lot cooler than they thought. And for those of you that were popular in high school, it's over, sorry. Thank you. Congratulations.

Leonard: Homo habilis discovering his opposable thumbs says what?
Kurt: What?

Leonard: I call Frodo!
Sheldon, Raj, and Howard: Damn!

Leonard: We all have other costumes, we can change.
Raj: Or we could walk right behind each other all night. It'll look like one person going really fast.