Leonard: Please don't let this be Sheldon playing bongos.

Howard: I got pretty exciting NASA news today. Next week I fly to Houston for orientation and zero-gravity elimination drills.
Penny: What does that mean?
Bernadette: He's gonna to learn to poop in space.
Howard: Open the pod bay doors, HAL.
Raj: Maybe your nickname should be "Brown Dynamite."

Amy: Don't be so hard on yourself. Do you know the story of Catherine The Great?
Penny: No.
Amy: She ruled Russia in the late 1700s and one night when she was feeling particularly randy she used an intricate system of pullies to have intimate relations with a horse.

Amy: Sheldon, you've never worked in a lab like this before. You have no experience in the field of biology.
Sheldon: I have plenty of experience in biology. I bought a Tamagotchi in 1998. And it's still alive. Let's do this.

Mrs. Wolowitz It's this dress. When I put my front in, my back pops out. When I put my back in, my front pops out. It's like trying to keep two dogs in a bathtub.
Sheldon: What do you want me to do?
Mrs. Wolowitz We're gonna have to work as a team. Get in here, grab a handful and start stuffing.

(Leonard is pointing out the monotonous movie habits of their former relationship.)
Leonard: No. You always picked, and it was always the same. An hour and a half of beach houses in the rain until the woman turns around and realizes love was here all along.
Penny: But, come on, that is a great movie, and it starts in ten minutes.

Barry Kripke: Listen to me. Not westauwant, westauwant. See, total cwap. You suck, Siwi!

Howard: Now, I downloaded an app that might be helpful in this situation.
[whip cracks]
Sheldon: You're right. I'm smart as a whip. I should be able to figure this out.

Sheldon: Hope you're not thinking about some sort of LSD thought control. Because there's only one mind-expanding drug this man enjoys, and that's called school.

Leonard: Do you think I'm overdressed?
Sheldon: It depends on the activity. For a prostate exam? Yes. If you're playing Vegas, I'd add sequins.

Jimmy Speckerman: Yeah, we were practically a comedy team.
Wolowitz: Yeah, like the Black Death and Europe.

Wolowitz: I'm so dehydrated. My pee's like toothpaste.

Sheldon: You just got off the list, would you like back on it?

Amy: Whee! Ooh, finally someone found second base.

Penny: You know I'm a big believer in breaking bad news to a guy when you're in bed with him. That's how I told my high school boyfriend I slept with his brother. That's how I told his brother the same thing.