Sheldon: When I try to deceive I have more nervous ticks than a lime disease research facility. It's a joke. It relies on a homonymic relationship between the tick the blood sucking arachnid, and tick the involuntary muscular contraction. I made it up myself.

Leonard: Sheldon lives in fear of the three-tined forks.
Sheldon: Three tines is not a fork. Three tines is a trident. Forks are for eating, tridents are for ruling the seven seas.

Penny: Okay, I got a box, but there's no key in here. Just letters.
Sheldon: That's the wrong box. Put it back.
Penny: Oh, Sheldon, are these letters from your grandmother?
Sheldon: Don't read those letters.
Penny: Oh, look, she calls you Moon Pie. That is so cute.
Sheldon: (shrieking) Put down the letters!

Sheldon: I've never once been invited to have cereal with Mrs. Vartabedian.
Leonard: She doesn't like you.

Penny: Mmm, what smells so good?
Sheldon: That is the intoxicating aroma of Kadhai Paneer. A perfect culinary representation of the freedom this evening holds. Not only is it Indian cuisine, which Koothrappali loathes, it contains a generous helping of peanuts, which would reduce Wolowitz to a wheezing 97-pound blister. And finally, its main ingredient is paneer, a farmer's cheese that would cause Leonard to render any room uninhabitable within minutes.

Penny: I'm curious. What was Leonard like when he was little?
Beverly Hofstadter: I think you mean young. He's always been little.

Penny: Looks like you've been to the Renaissance Fair ... I'm hoping.
Sheldon: Renaissance Fair? More of a medieval-slash-Age of Enlightment-slash-any-excuse-to-wear-a-codpiece fair.

Sheldon: We have a bowl. Our keys are in the bowl. You should get a bowl.
Penny: I just don't understand; how can beautiful mind of Sheldon Cooper forget his keys in the first place?
Sheldon: I left them in the bowl.

Mrs. Wolowitz Should I ask Leonard to bring over your homework?
Howard: I don't have homework. I'm a grown man with a master's degree in engineering.
Mrs. Wolowitz Excuse me, Mr. Fancy Pants. Want me to get you a popsicle?

Sheldon: Fellow warriors, this is Sheldor the Conqueror. We are about to enter Atzel's fortress. Now, this is a long run, so let's do another bladder check. All right, Barry, we'll wait for you again, but you really should see a doctor.

Raj: Welcome to the Raj Majal.

Sheldon: That's preposterous. I do not resemble C-3PO. Don't get me wrong, I'm flattered. I just don't see it.

Sheldon: I am very, very sorry for what I have done. Here's your laundry, I rescind your strikes and you are no longer banished.

Sheldon: Camouflaging bald spots. That's primarily a male concern. Perhaps we could expand our market.
Penny: How are flower barrettes going to appeal to men?
Wolowitz: We add Bluetooth.

Sheldon: (To Penny) Apparently, I'm in some kind of relationship, and, well, you seem to be an expert at ending them.
Penny: Excuse me?
Sheldon: I see man after man leaving this apartment never to return.
Penny: Okay, first of all, it is not man after man.