Sheldon: I recently read that during World War Two, Joseph Stalin had a research program to create supersoldiers by having women impregnated by gorillas.
Howard: What a sick use of science.
Raj: Hey, as long as the baby's healthy.
Amy: I wonder if Stalin considered any other animals.
Leonard: Hippos are the deadliest creature. A half-human, half-hippo soldier would be pretty badass.
Howard: Yes, but when they're hungry-hungry, you can stop them with marbles.
Sheldon: Yeah, the correct animal for interspecies supersolider is koala. You would wind up with an army so cute it couldn't be attacked.

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: Hey, Sheldon, did you change your Wi-Fi password again?
Sheldon: Yes, it's "Penny, get your own Wi-Fi." No spaces.