Sheldon: Alright, I think we're going to need some ground rules. In addition to the expected no shoes in the time machine and no eating in the time machine, I propose that we add pants must be worn at all times in the time machine.
Leonard: Seconded.
Howard: I was going to put down a towel.

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: Oh, I have a solution. First go into the future and obtain a cloaking device.
Raj: Ooh, how far into the future?
Sheldon: If I remember correctly, Captain Kirk will steal a cloaking device from the Romulans on Stardate 5027.3, which will be January 10th 2328 by pre-federation reckoning.
Leonard: Okay, I am setting the dials for January 10th, 2328.

Sheldon: Why did you set it for the day before yesterday?
Leonard: Because I want to go back and keep myself from getting a time machine.
Sheldon: You can't. If you were to prevent yourself from buying it in the past, you would not have it available in the present to travel back and stop yourself from buying it, ergo you would still have it. This is a classic rookie time travel mistake.

Leonard: Uh, here's the thing. Girls like Penny never end up with guys who own time machines.
Sheldon: I disagree. Your inability to successfully woo Penny long predates your acquisition of the time machine. That failure clearly stands on its own.

Sheldon: In addition, your premise is flawed. In the original film, Rod Taylor got Yvette Mimeaux with that very time machine. In Back to the Future, Marty McFly got the opportunity to hook up with his extremely attractive young mother.
Leonard: Those are movies.
Sheldon: Well, of course they're movies. Were you expecting me to come up with an example involving a real life time machine? That's absurd.

Raj: Oh, I call dibs on the Golden Age Flash.
Howard: Hang on, I need that to complete my Justice Society of America collection.
Raj: Too bad, I called dibs.
Howard: Well you can't just call dibs.
Raj: I can and I did. Look up dibs on Wikipedia.
Sheldon: Dibs doesn't apply in a bidding war.

Howard: Mom, my bar-mizvah bonds, how much do I got? Thanks. I can go twenty six hundred dollars and two trees in Israel.
Leonard: Forget it guys. If I sell to one of you, the other two are going to be really mad at me.
Sheldon: Who cares, as long as you pick me.

Sheldon: Oh, and one more thing, it's on bitch.

Sheldon: What rat have you recruited to the SS sinking ship?
Leslie: Hello Sheldon.
Sheldon: Leslie Winkle.
Leslie: Yeah Leslie Winkle. The answer to the question, who made Sheldon Cooper cry like a little girl?
Sheldon: Yes well I am polymerised tree saps and you are an inorganic adhesive so whatever verbal projectile you launch in my direction is reflected off me, returns on its original trajectory and adheres to you.
Leslie: Oh, ouch.

Sheldon: You want me to use my intelligence in a tawdry competition? Would you ask Picasso to play Pictionary? Would you ask Noah Webster to play Boggle? Would you ask Jacques Cousteau to play Go Fish?

Leonard: Come on, you need a four-person team. We're four people
Sheldon: By that reasoning we should also play bridge, hold up a huppah and enter the Olympic bobsled competition.

Howard: Don't you think I should answer the engineering questions? I am an engineer.
Sheldon: By that logic I should answer all the anthropology questions because I'm a mammal.

Sheldon: Look, you may have democracy in your beloved Russia, but on this physics bowl team, I rule with an iron fist. (Raising his fist) Ow!

Sheldon: I need my wrist brace. All this button pushing is aggravating my old Nintendo injury.