Sheldon: What can we do that's fun?
Leonard: What can we do that's different?
Penny: What can we do that's free?

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

Penny: I mean, who even reads Scientific American?
Leonard: It's kind of a big deal.
Penny: If it's such a big deal, how come the biggest celebrity they could get for the cover is a molecule?

Sheldon: Woman, you are playing with forces beyond your ken.
Penny: Yeah, well your Ken can kiss my Barbie.

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?

Raj: Hey, listen to this. Murder, cannibalism and satanic rituals are just a few of the thousand-plus horrors that await.
Howard: I just helped my mum out of the tub, so I'm one slippery horror ahead of you.

Raj: You know when Cinnamon won't take her medicine. I hide it in a piece of cheese.
Howard: Good idea. We can wrap up the pill in cheese, feed it to Cinnamon and then my mom can eat Cinnamon.