Leonard: Hang on, hang on. Are all those things equal to you?
Sheldon: Hmm, it never occurred to me to pick a favorite.
Leonard: Give it a go.
Sheldon: I can't answer that without collecting additional data.
Leonard: "Additional data", you dog!
Sheldon: I'm not sure how listening to other nine-fingered banjo players makes me a dog, but all right.

Sheldon: You are effectively paying yourself five dollars and nineteen cents a day.
Penny: A day?
Sheldon: There are children working in sneaker factories in Indonesia who out-earn you.

Sheldon: If I would give you this gift basket, based on that action alone and no other data, infer and describe the hypothetical relationship that exist between us.
Store Clerk: Excuse me?
Sheldon: Here. Now, are we friends? Colleagues? Lovers? Are you my grandmother?
Store Clerk: I don't understand what you're talking about and you're making me a little uncomfortable.
Howard: See? Sounds just like you and Penny. We'll take it.

Sheldon: Given the reaction to my costume, this party is a scathing indictment of the American educational system.
Kurt: You're a zebra, right?
Sheldon: (to Leonard) Yet another child left behind.

Sheldon: Doctor Greene, question?
Dr. Greene: Yes?
Sheldon: You've dedicated your life's work to educate the general populous about complex scientific ideas.
Dr. Greene: Yes, in part.
Sheldon: Have you ever considered trying to do something useful? Perhaps reading to the elderly?
Dr. Greene: Excuse me?
Sheldon: Yeah, but not your books. Something they might enjoy. I kid of course, big fan.

Penny: Really? On top of everything, you're afraid of birds?
Sheldon: Its called ornithophobia and someday it will be recognized as a true disability, and the landlord will be required by law to put a giant net over the building. Which is unfortunate because I have a fear of nets.

Sheldon: What are you doing here?
Leonard: I live here.
Sheldon: I have paperwork that says differently.

Sheldon: Hello. Well, this seems like an odd time to test my cell phone quality but go on. Test phrases. All right. Imatote. Ulba. Twad. All together? All right. I'm a total butt wad. Why are you laughing? Hello?
Penny: And that girls is how you make a phony phone call.

Sheldon: And here is my Justice League membership card, but that doesn't prove I know Batman.

Sheldon: Oh look, it's Harry Potter and 98% of Sorcerer's stone.

Sheldon: Howard, I have to go to the bathroom and no one will take me home.
Howard: What's wrong with the bathroom here?
Sheldon: Pneumococcus, streptococcus, staphylococcus and other assorted cocusses.
Howard: Sheldon, my mother is on her deathbed and my fiance is grief-stricken over putting her there. I'm not taking you home!
Sheldon: Will you at least go with me to the restroom here so you can open the door and flush the urinal?
Howard: No!
Sheldon: This might be a good time to point out, Howard, that friendship requires a certain give and take.

Penny: (Upset, about Kurt) 4 years, I lived with him. 4 years! That's like as long as high school.
Sheldon: It took you 4 years to get through high school?

Penny: Who's Adam West?
Sheldon: Who's Adam West!? Leonard, what do the two of you talk about after the coitus?

Sheldon: My new computer came with Windows 7. Windows 7 is much more user-friendly than Windows Vista. I don't like that.

Sheldon: But I have been getting better with sarcasm, if you want to give that a try.
Amy: *sarcastic* Oh, sure, I'd love to.
Sheldon: Whenever you're ready.