Raj: Now, the first thing we need is a theme. I'm thinking turn-of-the-century Moulin Rouge.
Leonard: I'm thinking you need a testosterone patch.

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.

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.

Bernadette: I told you you shouldn't have espresso after dinner. I know the little cups make you feel big but it's not worth it.

Sheldon: What can I do for you ladies?
Amy: You have something we want.
Sheldon: Oh, dear. My mother warned me this is what happens to pretty boys in the big city.
Penny: No, we just want information.
Sheldon: Oh. I've got that spades. Ravage me.

Sheldon: Did you also have a dog? Because I found what appears to be a battery-operated chew toy.
Penny: Party's over. Party's over.