Sheldon: Please don't take my looking forward to Leonard coming home as criticism of you in his absence. That criticism will come later in your report card.
Penny: Yeah, I didn't stay for the detention. I'm not going to read the report card.

Sheldon: Woman, you are playing with forces beyond your ken.
Penny: Yeah, well your Ken can kiss my Barbie.

Raj: [to Amy] If you were having Sheldon's baby, would you really want him in the room?
Penny: Yeah, if he's in the room when they're making the baby, I'll give you $10.

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?

Sheldon: Careful, Amy. The friend of the enemy's girlfriend is my enemy.
Amy: Really?
Sheldon: You're either with me or against me.
Amy: You wanna take the bus to work?
Sheldon: Maybe there's a third option.

Amy: What does tweepodoc mean?
Sheldon: Elephant?
Amy: Lucky guess.

Leonard: Leonard: I didn't make it back. The ship sank. I'm in Hell.