Raj: Come on, a medium-sized asteroid is still an interesting discovery.
Sheldon: I suppose it could end up on a collision course with Earth and destroy life as we know it.
Raj: You dream different than me.

Sheldon: Why did the chicken cross the Mobius Strip? To get to the same side. Bazinga!

Sheldon: I've seen things. Lady things.
Amy: Listen to me. That is not the way they usually look!

Leonard: Hey, I thought you were with your new buddies.
Sheldon: I had to leave. They were having fun wrong.

Leonard: Hey, can I talk to you about something? It's a little awkward.
Sheldon: I know what this is about. Given the professional standstill you're at, you're wondering if this is the appropriate time to abandon your research and focus on teaching. Yes! And if I may suggest, consider changing discipline. To the humanities or perhaps history. One of the advantages of teaching history is that you don't have to create things, you know, you just have to remember stuffs that happened and then parrot it back. You could have fun with that.

Leonard: I had a great idea. Do you know how we're always having to stop and solve differential equations, like when you're doing Fourier equations or using the Schroedinger equation?
Sheldon: Howard doesn't, he's only an engineer.

Sheldon: Milk Duds, with their self-deprecating name and remarkably mild flavor, are the most apologetic of the boxed candies.

Sheldon: Leonard, are you in the shower?
Leonard: I can't hear you, I'm in the shower.
Sheldon: I asked if you were in the shower, but that's moot now.
Leonard: What?
Sheldon: Moot. Rendered unimportant by recent events.
Leonard: I can't hear you, I'm in the shower.
Sheldon: (Entering bathroom) I have to skip the chitchat. Emergency!
Leonard: What kind of an emergency?
Sheldon: Mathematical. 32 ounce banana smoothie, 16 ounce bladder.

Mary Cooper: Sheldon's like a baby deer, you gotta let him come to you.

Sheldon: (To Penny) Apparently, I'm in some kind of relationship, and, well, you seem to be an expert at ending them.
Penny: Excuse me?
Sheldon: I see man after man leaving this apartment never to return.
Penny: Okay, first of all, it is not man after man.

Sheldon: New topic: women. Delightfully mysterious or bat-crap crazy?

Sheldon: Steven Hawking's a genius and he talks like a robot. It's everything I ever wanted in a friend.

Mike: I don't know what's scarier: the bathroom clowns or the woman that put them there?
Sheldon: All I know is you can only fit one of her in a car.
*Howard walks in*
Sheldon: And there's the clown that came out of her!

Leonard: You know what'd be nice? Name it after your girlfriends. Show them how much you care.
Raj: That is a great idea.
Sheldon: It's perfect. It appears romantic, but it's really just a rock in space that gets me out of Valentine's Day forever.
Raj: So, uh, what were you thinking? Combine their names?
Sheldon: I like it. Yeah, we'll take the "Am" from Amy and, uh, the "Y" from Emily.
Raj: That's just Amy.
Sheldon: Exactly. See how well we work together?

Sheldon: Good night. And if there's an apocalypse, good luck.