Leonard: Am I allowed to ask how the class is going?
Penny: It's really good. We've been talking about the origins of slavery. Turn in my first paper tomorrow.
Leonard: Great topic. I can help with that. There are lots of different perspectives you can take, economic, sociological, political.
Penny: Hey hey hey, this is my paper. And my perspective is that slavery is bad. Oh, and my professor's black, so I'm pretty sure thats the right answer.

Leonard: If I take it off, Sheldon wins.
Penny: Sweetie, every night you don't kill him in his sleep, he wins.

Penny: Sheldon, what did we say about being a nicer friend?
Leonard: Thank you.
Penny: Leonard, what did we say about being a gullible weeny?

Leonard: What am I supposed to do?
Penny: Err, keep your mouth off other women.

Leonard: I did a bad thing.
Sheldon: Does it affect me?
Leonard: No.
Sheldon: Then suffer in silence.

Stephen Hawking: What does Sheldon Cooper and a black hole have in common? They both suck.

Sheldon: Steven Hawking's a genius and he talks like a robot. It's everything I ever wanted in a friend.