Sheldon: I'm sorry, are we really doing this? Or are we tricking him again like with the dinner party?

Sheldon: Really? The only time I'm ever picked first for a team and I'm stuck with the liability?

Sheldon: My brain is better than everybody's!

Sheldon: I let you buy feminine hygiene products with my supermarket clubcard. Do you have any idea the kind of coupons I'm going to get in the mail now?

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.

Sheldon: No, no. You save your apologies for after you've had disappointing coitus with Penny.

Sheldon: This (Sailor's Hat) changes nothing. Except the Halloween costume I'm wearing this year. Amy, you're going to be Olive Oyl. Lay off the donuts.

Sheldon: You say you're from New Jersey, but how do I know?
Leonard: Who would lie about being from New Jersey?

Sheldon: There was obvious someone else in her apartment. I have no choice but to assume the worst, given Leonard's lengthy sea voyage and Penny's famously ravenous nether regions.

Sheldon: I'm quite familiar with plumbing. Not to brag, but I spent most of fifth grade with my head in a toilet.

Sheldon: That's curious. If there's no one here, why are there two glasses of wine on the table?
Penny: Oh, well you know. I've got two hands and a bit of a drinking prolbem.
Sheldon: Of course. Ask a silly question.

Sheldon: Have you got Leonard a welcome home gift?
Penny: No.
Sheldon: Do you want to go halfsies on a $200 squirt gun?

Sheldon: If my apples are mealy, we can hit the supermarket for one last blowout. I'll even let you push the trolley.

Sheldon: Penny, it's your lucky day. Three of these eggs are clearly not jumbo size. Grab your keys!

Sheldon: Stuart, I was wondering if you can help me find something.
Stuart: Happy to, unless it's hope or a reason to live?
Sheldon: Oh, you make me laugh, sad clown.