Leonard: What am I supposed to ask her? "Hey Penny, you got any friends that you never want to talk to again?"

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.

Bernadette: Does your mother call you every day at work to see if you had a healthy lunch?
Howard: My mother calls me every day at work to see if I had a healthy bowel movement.

Wil Wheaton: Game over, Moonpie.

Wil Wheaton: Did that guy just say "Revenge is a dish best served cold" to me in Klingon?