Penny: So you want me to be a teacher's pet?
Bernadette: Couldn't hurt.
Leonard: I don't know. Who here has ever been hurt because they were the teacher's pet?
*Sheldon, Amy, Howard, Leonard and Raj raise their hands*

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: [to a "smiling" Sheldon] We're here to see Koothrappali, not kill Batman.

Sheldon: You shot your spit in my mouth!
Howard: Is that gonna be on the test? Because I don't think I can do that again.

Amy: You better watch that attitude, buddy. You're dating the popular girl now.

Sheldon: The correct animal for inter-species super soldier is the koala. You would wind up with an army so cute, it couldn't be attacked.