Penny: Get away from me or I swear to God I will rip out what's left of your pubes!

Howard: He can't handle the fact that I'm a bigger deal than he is now.
Sheldon: Oh, preposterous. I have been solely responsible for this university's six loop quantum gravity calculations, I have changed the way we think about Bose-Einsten condensates, and I am also the one who got Nutter Butters in the cafeteria vending machine. Maybe you missed that news while you were floating around like a goof in outer space.

Leonard: What are you doing?
Wolowitz: Well, he wasn't using it, and I needed some cool leather to wiggle my naked ass on.

Howard: (Slams his car door) Will you please talk some sense into your lunatic roommate?
Leonard: You're both acting like lunatics!

Howard: Fine, I'm taking your diploma.
Sheldon: Go ahead. That's the only doctorate you'll ever get.

Sheldon: Give me back my parking space.
Howard: You don't need a parking space. You don't have a car.
Sheldon: You don't need an Iron Man helmet. You're not Iron Man.

Sheldon: Payback, it truly is the B word, isn't it?

Leonard: Howard did go to the International Space Station.
Sheldon: Yeah, that was five weeks ago. How much longer is he gonna milk that cow?

Howard: Well, we appear to have reached an impasse. And you know, I have to say, I thought you'd be more upset that your laptop is sitting on my junk.

Sheldon: Keep a lookout. This place is swarming with campus security. They will not hesitate to scold us.
Amy: Freaking pigs.

Sheldon: Well, Howard, thank you. It's quite a gesture on your part. You've shown yourself to be the bigger man.
Howard: Thank you.
Sheldon: Which I found totally unacceptable. I must be the bigger man. Therefore, you may use my spot until such time as I learn to drive or get a Batmobile.

Sheldon: A naked man sat on it. Now, here's my concern, his diet is rich in fatty deli meats. What tests do you have to detect lipid residue?
Store owner: Lipid what?
Sheldon: Lipid residue. An anal autograph. A colon calling card, if you will.