Leonard: Why should I do something? You're the one who introduced her to online gaming.
Sheldon: Well, yes, but you're the one who said hello to her when she moved in. If you'd just simply restrained yourself, none of this would be happening.

Penny: I meant has he ever been involved with someone who wasn't a brainiac?
Sheldon: Oh! Well, a few years ago, he did go out with a woman who had a Ph.D in French Literature.
Penny: How is that not a brainiac?
Sheldon: Well, for one thing she was French.

Sheldon: Whenever you're ready, AT&T!

Sheldon: You're in my bedroom.
Penny: Yeah, Leonard gave me an emergency key.
Sheldon: People can't be in my bedroom.

Sheldon: I'm hell-bent on catching a cyber criminal, not the common cold.

Penny: No, I can't. Sheldon, honey, I don't want things to be weird between us.
Sheldon: Won't it also be 'weird' if I have to say hello to you every morning on my way to work and you're living in a refrigerator box and washing your hair with rainwater?

Sheldon: Howard, I'm gonna need another mandarin lesson, I obviously didn't make my point with those people.
Howard: For God's sake, Sheldon, if you don't like the tangerine chicken, don't order the tangerine chicken.
Sheldon: I like tangerine chicken, I'm just not getting tangerine chicken.

Sheldon: # Nobody knows the trouble I've seen. Nobody knows my sorrow. #

Sheldon: There's a lot of harm in trying something new. That's why we test out drugs and cosmetics on bunny rabbits.

Sheldon: How would one measure a sense of humor? A humormometer?

Penny: I found the decaf.
Stuart: Oh, great.
Sheldon: Herbal tea for me, please.

Penny: How is that not talking to me like I'm an idiot? It's my friend, it's my couch, and it's my freakin' life!
Sheldon: It's also your roll.

Howard: What's this? (hand movement)
Sheldon:That's what you did. I assumed, as in a number of languages, that the gesture was part of the phrase.
Howard: Well, it's not.
Sheldon: Why am I supposed to know that? As the teacher, it's your obligation to separate your personal idiosyncrasies from the subject matter.

Leonard: Okay, I'm going ask you one more time. We did the work together, let's present the paper together.
Sheldon: And I'm telling you for the last time, it's pandering, it's undignified, and bite me.

Sheldon: *knock knock knock* Wil Wheaton!
*knock knock knock* Wil Wheaton!
Wait, how many was that?