Sheldon: 1234 is not a secure password.

Sheldon: Oh, what fresh hell is this?

Penny: Son of a bitch!
Leonard: Penny's up
Penny: You sick, geeky bastards!
Leonard: How did she know it was us?
Sheldon: I may have left a suggested organizational schematic for her bedroom closet.
Penny: Leonard!
Leonard: God this is going to be bad.
Sheldon: Good bye, Honey Puffs. Hello, Big Bran.

Sheldon: (To the smoking monkey) You really are an ass.

Sheldon: Impressive, but we must be cautious.
Howard: Why?
Sheldon: Today, it's a Chinese-food-retrieval robot. Tomorrow, it travels back in time and kills Sarah Connor.

Sheldon: What could I possibly have done to offend Mrs. Vartabedian?

Sheldon: I don't watch you twenty-four hours a day. I don't know what you do.

Penny: You're unbelievable.
Sheldon: I know.

Leonard: Okay Sheldon, to start our quest, you need to open this little Christmas gift I got you.
Sheldon: Christmas? You know I don't enjoy Christmas.
Stuart: Why not?
Sheldon: Oh, where to begin? Trees indoors. Overuse of the words 'tis' and 'twas'. And the absurd custom of one stocking. Everybody knows that socks comes in pairs. Who uses one sock?
Howard: A pirate with a peg leg?
Sheldon: Actually, that helps, thank you.

Penny: It's like if you're dating someone you're not that into and then they break up with you. Then you want them more than ever.
Sheldon: I have no idea what she's talking about, but we're ganging up on you so I agree.

Leonard: Sheldon, I promise, your uvula does not have an STD.
Sheldon: Are you sure? It just doesn't feel as innocent as it used to.

Leonard: Do you know how Penny told Raj he should have left her off his list.
Howard: Yeah.
Leonard: Do you think when she and I had that conversation she left people off her list?
Sheldon: I'm sure she did.
Leonard: Why?
Sheldon: Because if she hadn't, she'd still be wading through the list.

Sheldon: Oh, you don't need to worry about her. She's brilliant and attractive. She can do way better than Leonard.

Amy: My old scarf.
Sheldon: You wore it the night we went ice skating, remember?
Amy: You mean the night that I went ice skating and you stood at the rail Googling the symptoms of hypothermia.
Sheldon: We made one heck of a team, huh?

Sheldon: Excuse me, Barry?
Barry Kripke: Yes?
Sheldon: When can I stab one of my friends?
Barry Kripke: In fencing, we don't call it a stab. We call it a touch.
Sheldon: Uh, yes, I'm aware. But if I say I want to touch one of my friends, I'll get called into Human Resources.