Sheldon: For what it's worth, my mother says that when we deceive for personal gain, we make Jesus cry.

Sheldon: I gargled with tequila. I may have swallowed a tiny bit.
Leonard: You all right?
Sheldon: Fine, thank you for asking. I love you so much.

Leonard: How are we gonna get it upstairs?
Sheldon: If we take the dish off, it might fit in the elevator.
Leonard: Yes, but the elevator's been broken for two years.
Sheldon: I've been meaning to ask you, do you think we should make a call about that?
Howard: Not necessary, I have a master's in engineering. I remotely repair satellites on a regular basis. I troubleshoot satellite payloads. When the Mars Rover started pulling to the left, I performed a front-end alignment from 62 million miles away. (Pushing button on elevator) Nah, that baby's broken.

Sheldon: Leonard?
Leonard: What?
Sheldon: I am getting too old for this crud.

Sheldon: *Sees Leonard & Penny kissing* Oh, frickity frack. Not this again.

Sheldon: Amy Farrah Fowler, that's the most pragmatic thing anyone has ever said to me.

Sheldon: I was going to name him Hermann von Helmholtz, but he's so zazzy.

Wil Wheaton: Embrace the dark side.
Sheldon: That's not even from your franchise!

Raj: He's selling the Sword of Azeroth on eBay.
Leonard: You betrayed us for money? Who are you?
Sheldon: I'm a rogue Night Elf. Don't you people read character descriptions?

Sheldon: Knock Knock.
Leonard: Who's there?
Sheldon: Hugh.
Leonard: Hugh who?
Sheldon: Hugh guys ought to listen to me.

Sheldon: Yeah, I have to say I thought the toilet humor would get less funny with repetition. Apparently there is no law of diminishing comedic returns with space poop.

Sheldon: (Dictating) Research Journal, Entry One. I'm about to embark on one of the great challenges of my scientific career: teaching Penny physics.! I'm calling it "Project Gorilla".

Sheldon: Mmm, this is good. Whatever this is.

Sheldon: Your threats are empty. Nothing can move me.
(Howard drives his car slowly towards Sheldon, pushing his chair forward)
Sheldon: That's it! I'm calling campus security! You prepare for the scolding of your life!

Santa: All right, let me see if I've got this straight. A picture of you on my lap is a way to punish your girlfriend for making you celebrate Christmas?
Sheldon: Correct.
Santa: Santa thinks dating you might be punishment enough.
Sheldon: There's an argument for that, but I want to make sure.