Penny: Hey, hey, I just found a farm where they let you chop down your own tree.
Leonard: Oh cool, I'll be like a pointy-eared Paul Bunyan.

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.

Amy: Well, uh, Howard and Bernadette had their baby.
Mary Cooper: (gasps) Oh, that's wonderful! Now, have they decided to raise it Jewish or regular?
Sheldon: Welcome to Texas.

Bernadette: Everyone's a better mom than me.
Raj: Oh, don't take it so personally, maybe your baby's just a jerk.

Mary Cooper: Sheldon, if you're trying to prove me wrong, the tighty-whities on your head ain't changing my mind.