Penny: Honey, have you ever run before?
Sheldon: Certainly. I've run from bullies, dogs, angry chickens and one particularly persistent PE teacher determined to bend me over and give me a scoliosis test.

Howard: Don't you think I should answer the engineering questions? I am an engineer.
Sheldon: By that logic I should answer all the anthropology questions because I'm a mammal.

Sheldon: You did this, didn't you?
Wil Wheaton: Come on, Sheldon, do you really think I'd break up a couple just to win a bowling game?
Sheldon: No, I suppose not.
Wil Wheaton: Good. Keep thinking that.
Sheldon: Wheeeeatoooon!

Sheldon: In Papua New Guinea, there's a tribe when a hunter flaunts his success to the rest of the village, they kill him and drive away evil spirits with a drum made of his skin. Superstitious nonsense, of course, but one can see their point.

Sheldon: I need to sleep here tonight.
Raj: Why?
Sheldon: Howard is a total ass, Bernadette is in Penny's bed, Amy bites and Penny may or may not have coitus with Leonard.
Raj: Okay, come in.

Sheldon: The mean Indian lady tried to make me eat lamb.

Penny: I always tear up when the Grinch's heart grows three sizes.
Sheldon: Tears seem appropriate. Enlargement of the heart muscle, or hypertrophic cardiomyopathy, is a serious disease which can lead to congestive heart failure.

Sheldon: I read an article about Japanese scientists who inserted DNA from luminous jelly fish into other animals; and I thought "Hey! Fish night-lights".
Leonard: Fish night-lights.
Sheldon: It's a billion dollar idea, ssh!

Sheldon: I know mother, but you're not fooling me. Every time you want to talk it means you want me listen.
Mrs. Cooper: Then stop talking.
Sheldon: Yes, Ma'am.

Penny: Sheldon, did you have a Christmas tree?
Sheldon: Oh, yes. We had a tree, we had a manger, we had an inflatable Santa Claus with plastic reindeer on the front lawn. And to make things even more jolly, there were so many blinking lights on the house they induced neighborhood-wide seizures.

Sheldon: You may have gone to Cambridge but I'm an honorary graduate of Starfleet Academy.

Mary Cooper: Honey, why did you get a loom?
Sheldon: Well, I was working with luminous fish and I thought, hey, loom.

Sheldon: There's a fine line between wrong and visionary. Unfortunately, you have to be a visionary to see it.

Sheldon: I made a new friend who likes trains as much as I do, I kissed Amy on the lips, and the conductor played his banjo for me.

Sheldon: When you understand the laws of physics, Penny, anything is possible. And may I add, "Mwah, ha, ha."