Sheldon: How many Edisons does it take to screw in a light bulb?
Amy: How many?
Sheldon: Who cares he stole the idea and doesn't deserve his own joke.

Amy: Sheldon, there's something else I've been wanting to say, but before I do, I just... I want you to know that you don't have to say it back.I know you're not ready, and I don't want you to say it just because social convention dictates...
Sheldon: I love you, too.
Amy: You said it.
Sheldon: There's no denying I have feelings for you that can't be explained in any other way. I briefly considered that I had a brain parasite. But that seems even more far-fetched. The only conclusion was love.

I obviously have the flu, coupled with sudden on-set Tourette's Syndrome.

Until you manage to upload your intelligence into a self-sustaining, orbiting satellite equipped with high-speed internet and a cloaking device, you will be dependent on the human race.

Amy: This year's donations may go to, say, the geology department.
Sheldon: Oh dear, not the dirt people.

You don't have to be strong for me. Now let's talk about Priya that man stealing bitch.

I'm regretting my earlier cattiness; she's an absolute delight.

Granted, Penny, your secondary sexual characteristics are reasonably bodacious, but Priya is highly educated, she's an accomplished professional, and she comes from the culture that literally wrote the book on neat ways to have sex. Whereas you on the other hand are a community college dropout who comes from the culture that wrote the book on tipping cows.

Good news! Thanks to you I was able to make a rhesus monkey cry like a disgraced televangelist.

Bernadette: Leonard's really one of a kind.
Amy: Saying that while holding a snowflake is a bit heavy-handed don't you think?

I'm prone to night terrors, so if I wake up kicking and screaming, don't panic. Just pin me down and stroke my hair and I'll be fine.

Amy: I have potential for sexual arousal.
Sheldon: A cross we all must bear.

TBBT Quotes

Penny, there's only one cookie with something in the middle that solves life's problems, and that's an Oreo. Or a Nutter Butter, if you're in a pinch.

Sheldon

Penny: Here's a question-- as an alien pretending to be human, are you planning to engage in any post-prom mating rituals with Amy?
Sheldon: There are post-prom mating rituals?
Penny: Not always. Unless your date drives a van with an air mattress, then always.
Sheldon: Well, if it's part of the prom experience, then I'm open to it.
Penny: You're kidding.
Sheldon: I may be an alien, but I have urges.If Amy wants to copulate by firing her eggs into space, well, then, I will happily catch them with the reproductive sac on my upper flermin. I'm not the best at reading facial cues, but I can see that you're a little turned on.