Penny: So, are we celebrating anything special tonight?
Amy: Oh, yes. Our relationship agreement specifies that the second Thursday of every month, or the third Thursday in a month with five Thursdays, is date night.
Penny: That is so hot.

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?

Howard: I'm not signing a prenup.
Penny: All right, Howard Wolowitz, listen up! You sign anything she puts in front of you, because you are the luckiest man alive. If you let her go, there is no way you can find anyone else. Speaking on behalf of all women, it is not going to happen, we had a meeting.

Amy: Jewelry? Seriously? Sheldon, you are the most shallow, self-centered person I have ever met! Do you really think another transparently manipulative - Oh, it's a tiara! Put it on me, put it on me, put it on me, put it on me.

Penny: You look beautiful.
Amy: Of course I do, I'm a princess and this is my tiara!

Sheldon: Hard as this may be to believe, it's possible that I'm not boyfriend material.
Leonard: Glad I was sitting down for that.