Penny: Don't you dare knock!

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

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

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

Raj: If I could speak the language of rabbits, they would be amazed, and I would be their king.
Leonard: I hate my name. It has 'nerd' in it. 'Len. Nerd.'
Wolowitz: I lost my virginity to my cousin Jeanie.
Raj: I would be kind to my rabbit subjects. At first.

Wolowitz: You're such a douche
Raj: Who cares? You slept with your cousin!

Sheldon: Now remember, you were given powerful pain medication and a muscle relaxer, so don't operate heavy machinery, and try not to choke on your own drool. [goes to leave] Penny: Wait! You have to help me get into bed. [laughs] "Sheldon has to help me get into bed". Bet you thought I'd never say that!
Sheldon: Yes. Charmed. Your drug-addled candor knows no bounds. [helps Penny into bed]
Penny: You know people think you are this weird robot man who's so annoying all the time and you totally are. But then it's like that movie Wall-E at the end. You're so full of love and you can save a plant and get fat people out of their floaty chairs.
Sheldon: That's a fairly labored metaphor but I appreciate the sentiment behind it.