Sheldon: Amy, I find myself wondering if we should actually engage in coitus at least one time in our relationship. Bazinga! Bedtime. Please show yourself out.

Sheldon: I'll be Coop and he'll be Wheels. If he's okay with that.

Amy: I'm just really glad you're back.
Sheldon: Me too. I've got a lot of TV to catch up on.

Leonard: Are you set on people laughing WITH you? Because if you're cool with AT you ...
Sheldon: I don't get it.

Sheldon: (Running from the angry mob) Why is there never a pontoon plane when you need one?

Sheldon: Koko learned to understands over 2000 words, not one of which had anything to do with shoes.

Kripke: I'm Barry Kripke and I'm here because you told me there was a raffle. Where is the raffle?
Sheldon: Patience, patience, Barry, the waffle-- ahem. The raffle... is the grand finale to an evening-long festival of fun and folly.
Kripke: One more question--
Sheldon: Yes, you must be present to win.

Sheldon: Goodnight puny human!

Sheldon: "Sheldon's Mine Simulation Log, entry 4: My KitKat has melted. All is lost."

Penny: I thought they fired you guys.
Sheldon: They did, but then they hired me back.
Leonard: Well, you better not be working on our project, because we're a team.
Sheldon: Leonard, there is no "I" in team. However, there is an "I" in "I'm working with the military and you're not." There's five of them, in fact.

Howard: You're either on Team Leonard or Team Penny.
Sheldon: Which one picks last?
Howard: What?
Sheldon: Well, usually I'm on the team that picks last. Unless there's a kid in the wheelchair.

Sheldon: First, talking to you while you're on the toilet isn't exactly a picnic for me either. Remember, when you can hear me, I can hear you.

Howard: All I know is he's got my mother buying four ply toilet paper. Four ply! If his butt is so delicate, why doesn't he use an Angora rabbit?
Sheldon: For starters, they shed and bite.

Sheldon: But I need it. It's the only way to settle the contradictions between gravity and quantum mechanics.
Penny: Well, it's too much money, you can't ask for that all at once.
Sheldon: Well, what if I ask for it in six easy installments of $83,333,333.33?

Sheldon: Hello?
Leonard: Oh, hey, where you been? We've been calling you for hours.
Sheldon: Oh, I'm sorry, my phone was on "airplane" mode.
Leonard: Why?
Sheldon: Because I was on an airplane. (makes confused gesture to Amy)