Sheldon: No, go ahead, say it. I know what it is. I've heard it my whole life. The word's "annoying." Go ahead, say it. Say it. Say I'm annoying.
Amy: Sheldon...
Sheldon: Oh, it won't hurt my feelings. Go ahead, Amy, say I'm annoying. I'm annoying. I'm annoying. I'm annoying.

Dr. Jeffries: Hold on. You ... you have a girlfriend?
Amy: Hey look -- we're wearing the same orthopedic shoes. I can't believe I dress like a celebrity.
Dr. Jeffries: O-Okay, I get it now.

Amy: So you just got lucky?
Sheldon: Sheldon Cooper doesn't get lucky.
Amy: You and me both.

Amy: Sheldon, you're not a weirdo.
Sheldon: I wasn't speaking about me.

Sheldon: You sure your mothlike personality won't be drawn to this blazing fire that is myself?
Amy: More and more sure.

I'm hoping to put his love of repetition to good use someday.

Amy: ... if he weren't in the movie, the Nazis would have still found the ark, taken it to the island, opened it up and all died ... just like they did.
Sheldon: [jaw dropped]
Amy: Let me close that for you.

Indiana Jones plays no role in the outcome of the story.

Amy: When you told me I was going to be "losing my virginity," I didn't think you meant you'd be showing me Raiders of the Lost Ark for the first time.
Sheldon: My apologies. I chose my words poorly. I should have said you were about to have your world rocked on my couch.

Sheldon: To the planetarium!
Penny: Let's go!
Leonard: To the Tar Pits!
Bernadette: Let's go!
Amy: There's a Neil Diamond concert next month.
Howard: Let's go!

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

Penny: He's still mad at Leonard, huh?
Amy: Well, he's mad at you, too. He said you were the succubus that led his friend astray.
Penny: I don't know what succubus is, but it has "suck" in it, so that can't be good.

TBBT Quotes

It's very simple. Scissors cuts paper, paper covers rock, rock crushes lizard, lizard poisons Spock, Spock smashes scissors, scissors decapitates lizard, lizard eats paper, paper disproves Spock, Spock vaporizes rock, and, as it always has, rock crushes scissors

Sheldon

Sheldon: Why do you have the Chinese character for "soup" tattooed on your right buttock?
Penny: It's not "soup," it's "courage."
Sheldon: No it isn't. But I suppose it does take courage to demonstrate that kind of commitment to soup.
Penny: How'd you see it? You said you wouldn't look.
Sheldon: Sorry. As I told you, the hero always peeks.