Leonard: When he wasn't happy, we wanted to kill him. There was even a plan. We were going to throw his Kindle outside, and when he went to get it, lock the door and let him freeze to death.
Sheldon: That seems like a bit of an overreaction.
Leonard: No, the overreaction was the plan to tie your limbs to four different sled-dog team and yell "Mush!"

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Leonard: Penny. We are made of particles that have existed since the moment the universe began. I like to think those atoms traveled fourteen billion years through time and space to create us, so that we could be together and make each other whole.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Mary Cooper: Raj is it? Still having trouble talking to the ladies? Because you know at our church we have a woman who's an amazing healer. Mainly she does crutch and wheelchair people. But I bet she'd be willing to take a shot at whatever third-world demon is running around inside of you.

Howard: Sheldon, you remember the first few weeks we were looking for magnetic monopoles and not finding anything, and you were acting like an obnoxious, giant dictator?
Raj: I thought we were going to be gentle with him.
Howard: That's why I added the '-tator'.

Sheldon: What are they doing here?
Leonard: We came to apologize again and bring you home. So why don't you pack up your stuff, and we'll head back?
Sheldon: No, this is my home now. Thanks to you, my career is over, and I will spend the rest of my life here in Texas trying to teach evolution to creationists.
Mrs. Cooper: You watch your mouth, Shelly. Everyone's entitled to their opinion.
Sheldon: But evolution is not opinion, it's a fact.
Sheldon's mom: And that is your opinion.