Howard: Kind of a "Mars rover, Mars rover, can Howard come over?" situation.

Raj: Lock up your daughters, we're going to hit it and quit it.

Wolowitz: Qu'est-ce que 'sup?

Penny: Oh, I didn’t tell you? You’re banished from the Cheesecake Factory.
Sheldon: Why?
Penny: Well, you have three strikes. One, coming in. Two, sitting down. And three, I don’t like your attitude.

Dr.Gablehauser: Need to get that, Dr. Cooper?
Sheldon: God, no.
Leslie: Don't turn it off, you might miss the Nobel Prize Committee saying that you won "Dumbass Scientist of the Year."

Penny: I'll tell you what happened. (sigh) We were young. We were very much in love, but we could only communicate through a time-travelling mailbox at my lake house.
Sheldon: It's not enough that you made me watch that movie, but now you mock me with it?

Penny: Look, Sheldon, I'm really, really sorry but it's only going to be for a week. Can't you be a little bit flexible?
[Leonard, Howard, Raj and Sheldon all look at her]
Penny: Yeah, sorry, I didn't really think that through.

Sheldon: (On computer screen) Hello, puny insects, as a consequence of your efforts to circumvent my will, everyone is awarded one additional strike.
Leonard: Thanks a lot, Howard.
Howard: What are you complaining about? I'm the one who has to take the class again.

Penny: I was in junior rodeo. I can hog-tie and castrate him in 60 seconds.

Sheldon: Hey! Look I found my missing neutrino.
Howard: Oh, great! We can take it off the milk carton.

Sheldon: Oh, Penny. I know you think you're being generous, but the foundation of gift-giving is reciprocity. You haven't given me a gift, you've given me an obligation.
Howard: Don't feel bad, Penny. It's a classic rookie mistake. My first Hanukkah with Sheldon, he yelled at me for eight nights.

Penny: Where are my clothes?
Sheldon: Your clothes?
Penny: Yes. I left them in the washers and when I went down to get them, they were gone.
Sheldon: Really? Despite the sign that says: "Do not leave laundry unattended?"

Sheldon: Look on the bright side.
Leonard: What's the bright side?
Sheldon: Only 9 more months to Comic-Con.

Sheldon: Why don't you just take your clothes down to the river and beat them with a rock.

Leslie: You agree with me, right, loop quantum gravity is the future of physics.
Leonard: Sorry Leslie, I guess I prefer my space stringy not loopy.
Leslie: Well, I'm glad I found out the truth about you before this went any further.
Leonard: Truth, what truth? We're talking about untested hypotheses, uh, it's no big deal.
Leslie: Oh, it isn't, really? Tell me Leonard, how would we raise the children?