[Sheldon karate chops Leonard in the shoulder]
Leonard: Ow! Why did you do that?
Sheldon: To send a message: she's not for you!
Leonard: What?
Sheldon: Not for you!

Raj: Come on, Sheldon, Star Wars.
Howard: I'm pushing play. I mean it. If we don't start soon, George Lucas is going to change it again.

Wolowitz [about his phone call]: Looks like I'm going to have sex tonight
Penny: His right hand is calling him?

They can't just cancel a show like Alphas. You know? They have to help the viewers let go. Firefly did a movie to wrap things up. Buffy the Vampire Slayer continued on as a comic book. Heroes gradually lowered the quality season by season till we were grateful it ended.

Sheldon

I have to say I thought the toilet humor would get less funny with repetition. Apparently there is no law of diminished comedic returns when it comes to space poop

Sheldon

Raj: Woh, woh, woh! I don't want to speak to the FBI.
Leonard: Why not?
Raj: I'm brown and I talk funny.

Leonard: Why do I have to talk to Penny? She's not my girlfriend.
Sheldon: You invited her to lunch four years ago, everything about her is on you: you make it so!

But e-excuse me, I have something to say. None of you may realize it, but I was very much looking forward to this weekend. It was gonna be like the old days -- the four of us hanging out, playing video games, before you guys all got girlfriends. Do you have any idea what its like to the be the only one without a girlfriend? Even if I get one someday, I'll still be the guy who got a girl after Sheldon Cooper!

Raj

But if she dumps you, she'll have a new boyfriend by tomorrow morning, and you'll have a new girlfriend when you figure out how to build one.

Wolowitz

Sheldon: I can't seem to get in touch with Amy. I tried e-mail, video chat, tweeting her, posting on her Facebook wall,texting her, nothing.
Leonard: Did you try calling her on the telephone?
Sheldon: The telephone. You know, Leonard, in your own simple way, you may be the wisest of us all.

It is to viagra as viagra is to a green M&M.

Sheldon

Raj: The only thing I've learned in the last two hours is that American men love drinking beer, pee too often, and have trouble getting erections.
Leonard: Focus on the game, not the commercials, Raj.
Raj: I'm just saying, maybe if you people cut back on the beer, you could get out of the bathroom and satisfy your women without pharmaceutical help.

TBBT Quotes

Oh, Bernadette, please play my clarinet.

Raj's poem

Sheldon: I'll have a diet Coke.
Penny: Can you please order a cocktail? I need to practice mixing drinks.
Sheldon: Fine... I'll have a virgin Cuba Libre.
Penny: That's... rum and Coke without the rum.
Sheldon: Yes, and would you make it diet?