Penny: Come on. What about the living organism of the workforce and the American spirit and Jiminy Crockett at the Alamo?
Leonard: Davy Crockett. Jiminy Crockett was a cricket.

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.

Sheldon: I'm sorry, coffee's out of the question. When I moved to California I promised my mother that I wouldn't start doing drugs.

Sheldon: You are effectively paying yourself five dollars and nineteen cents a day.
Penny: A day?
Sheldon: There are children working in sneaker factories in Indonesia who out-earn you.

Sheldon: Camouflaging bald spots. That's primarily a male concern. Perhaps we could expand our market.
Penny: How are flower barrettes going to appeal to men?
Wolowitz: We add Bluetooth.