Howard: How did you get so brave all of a sudden?
Raj: It's easy. The spider's crawling up your arm.

Raj: Ok, two words. Deaf chick. It doesn't matter if I can't talk because she can't hear me.
Leonard: What?
Raj: That's what she said.

Penny: Ooh, these are cute. Of course if I buy them, I'll have to rent my womb out to a gay couple.

Sheldon: Well, if it isn't Wil Wheaton, the Jar-Jar Binks of the Star Trek Universe!
Wil Wheaton: (Imitating Jar-Jar) Me-sa think that's funny.

Sheldon: She is a girl, who is a friend, but she is not, forgive me for doing this, (air quotes) "my girlfriend".

Sheldon: I'm no stanger to mimetic epidemiology. At Johnson Elementary school, the phrase Shelly Cooper's a smelly pooper spread like wildfire.
Amy: I should think so, that's gold.

Amy: I came as quickly as I could.
Penny: Ok, why?
Amy: To comfort you, of course. Sheldon told me about Leonard dating Rajesh's sister, so I high-tailed over here to pick up the pieces of your broken heart.
Penny: Amy, I'm fine.
Amy: You don't have to be strong for me. Now, let's talk about Priya, that man-stealing bitch.

Sheldon: Greetings, friends.
Leonard: (To Robot Sheldon) Greetings, whatever-the-hell you are.

Sheldon: Raj! What are you doing?
Raj: *raises coffee cup*
Sheldon: I don't think so. You've already had your allotted 6 ounces. The next bathroom break isn't until the Denny's near Bakersfield, which is approximately 2 and a half hours away. Remember people, we're only as strong as our weakest bladder.

Wyatt: I want grandkids before I die and I want 'em to grow up in a house without wheels.

Sheldon: I don't understand why you're not enjoying this. Together, in this car, with my enhanced capabilities, we're like Knight Rider.
Leonard: Except in Knight Rider the car isn't a yammering sphincter.
Sheldon: You mock the sphincter, but the sphincter is a class of muscle without which human beings couldn't survive. There are over 50 different sphincters in the human body. How many can you name?
Leonard: I was wrong. This is exactly like Knight Rider.

Raj: Oh Leonard, you remind me of the funny old story of the man who walks into a Women's Correctional Facility with a stack of paperwork that would allow the female convicts to go free.
Leonard: You're saying I couldn't get laid in woman's prison with a handful of pardons.
Raj: Are you going to let me tell the story or not?

Howard: I'm guessing 21 seconds had something to do with that too.

Raj: Please don't send me back to India, it's so crowded! Its like the whole country's one endless Comic-Con, except everybody is wearing the same costume; Indian guy!

Bernadette: What's George Takei doing here?
Katie Sackhoff: Howard, do you have latent homosexual tendencies?
Howard: Of course not.
George Takei: So you say, yet here I am.