Leonard: What the hell are you doing?
Sheldon: I'm making petri dishes to grow throat cultures.
Leonard: With lime jello?
Sheldon: I need a growth medium, and someone polished off the apricot yogurt. Here, swab my throat.

Penny: Sheldon, what are you doing here?
Sheldon: I'm sick, thank you very much.
Penny: How could you have gotten it from me? I'm not sick.
Sheldon: You're a carrier. All these people here are doomed. You're doomed!

Penny: Okay, what kind of soup do you want?
Sheldon: Well, my mother used to make me this split pea with little frankfurter slices and these home made croûtons.
Penny: We have Chicken Tortilla and Potato Leek.
Sheldon: Can I get any of those with little frankfurter slices and home made croûtons?
Penny: No.
Sheldon: Then surprise me.

Penny: Sheldon, you are a grown man, haven't you ever been sick before?
Sheldon: Well, of course, but, not by myself.
Penny: Really, never?
Sheldon: Well, once. When I was fifteen, and spending the summer at the Heidelberg Institute in Germany.
Penny: Studying abroad?
Sheldon: No, visiting professor. Anyway, the local cuisine was a little more sausage-based than I'm used to, and the result was an internal blitzkrieg with my lower intestine playing the part of Czechoslovakia.

Sheldon: Do you think Penny will come here and take care of us?
Leonard: I don't think Penny’s ever coming here again.
Sheldon: I'm very congested.
Leonard: Yeah, so?
Sheldon: Can you go to the kitchen, and get me the turkey baster labeled mucus.
Leonard: If I stand, I'll vomit.
Sheldon: Under the sink, yellow Tupperware bowl.

Raj: I still want it on my balcony. I say we move it on a bi-monthly basis.
Leonard: That sounds fair.
Sheldon: Hold on. Bi-monthly is an ambiguous term, do you mean move it every other month, or twice a month?
Raj: Twice a month.
Sheldon: Then no.
Raj: Okay, every other month.
Sheldon: No.

Sheldon: I feel very comfortable around you.
Beverly Hofstadter: I feel very comfortable around you, too.
Sheldon: It's surprising because I generally dont feel comfortable around, well, anyone.
Beverly Hofstadter: Nor I.
Sheldon: What are the odds that two individuals as unique as ourselves would be connected by someone as comparatively workaday as your son?
Beverly Hofstadter: Is that a rhetorical point or would you like to do the math?
Sheldon: I'd like to do the math.
Beverly Hofstadter: I'd like that, too.

Raj: Sheldon, I'm begging you. I want to go to this mixer, and I don't want to go alone.
Sheldon: Well, you're in luck. There's a mixer here in Flatland. Oh, look, there's a sexually attractive line segment, you should chat her up.
Raj: What?
Sheldon: Tell her you're a circle. Flatland gals are all hot for circles.

Amy: I've come up with a series of exercises to help with your compulsive need for closure.
Sheldon: I take issue with the word compulsive.
Amy: All I'm saying is, we live in a world where closure isn't always an op...
Sheldon: -tion. Okay. For the sake of argument, let's say I have a problem. What would be your plan for addressing it?

Sheldon: Yes. I play the word quiver with a triple letter and a double word score for 72 points. That ought to let the air out of your tires, Hawking.

Amy: Oh, you could turn his act into extract, and it would be for double points.
Sheldon: Amy. Why would you give me a word? Now, if I play extract it would be cheating.
Amy: Sorry.
Sheldon: Although, I could play the completely unrelated and better word extract. Ethical conundrum avoided. Thanks, brain.

Sheldon: Alright, and this is my office.
Dennis Kim: Is this part of the tour?
Sheldon: Nope. Goodbye.
Leonard: Come on, Sheldon, we've hardly shown him anything.
Sheldon: Oh, alright. This is my desk, these are my books, this is my door, please close it behind you. Goodbye.

Leonard: You can't let this kid get to you. You always knew that someday someone would come along who was younger and smarter.
Sheldon: Yes, but I assumed I would have been dead hundreds of years, and that there would be an asterisk by his name because he would be a cyborg.

Penny: So, you've got a bit of competition, I really don't see what the big deal is.
Sheldon: Well of course you don't, you've never excelled at anything.

Sheldon: What exactly is it you do? I know you chatter on about it all the time, but I've never really paid attention.
Leonard: Okay, well, right now I'm designing an experiment to study the soft component of cosmic radiation at sea-level, but I really don't need any help.
Sheldon: Oh, sure you do. Now, see, what's this here in the schematic, is that a laser array?
Leonard: Yes.
Sheldon: Now, hmmm. What happens if you use argon lasers instead of helium neon?
Leonard: It would blow up.
Sheldon: Are you sure?
Leonard: Pretty sure.
Sheldon: Pretty sure's not very scientific. Is this how you normally work, just hunches and guesses and stuff?