Sheldon: I couldn't sleep knowing that just outside my bedroom is our living room and just outside our living room is that hallway and immediately adjacent to that hallway is [Penny's messed up apartment]!
Leonard: Do you realize if Penny wakes up there's no reasonable explanation to why we are here?
Sheldon: I just gave you a reasonable explanation.
Leonard: No, no. You gave me an explanation. Its reasonableness will be determined by a jury of your peers.
Leonard: If you don't have any other plans, do you want to join us for Thai food and a Superman movie marathon?
Penny: A marathon? Wow, how many Superman movies are there?
Sheldon: You're kidding, right?
Leonard: I guess we'll just take [a TV cabinet] up [the stairs] ourselves.
Sheldon: We don't have a dolly, or lifting belts, or any measurable upper-body strength.
Leonard: We don't need strength. We're physicists. We are the intellectual descendants of Archimedes. Give me a fulcrum and a lever, and I can move the Earth. (Trying to move the box) It's just a matter of... I don't have this. I don't have this. I don't have it!
Sheldon: Archimedes would be so proud.
Sheldon: Oh Gravity, thou art a heartless b*tch.
Leonard: Most people don't sort their breakfast cereal numerically by fiber content.
Sheldon: Excuse me, but I think we've both found that helpful at times.
Leonard (trying to get Sheldon to leave Penny's apartment in the middle of the night): Sheldon, this is not your home!
Sheldon: This isn't anyone's 'home'. This is a swirling vortex of entropy.
Leonard: For God's sake, Sheldon, do I have to hold up a sarcasm sign every time I open my mouth?
Sheldon (intrigued): You have a sarcasm sign?
Leonard (looking at the heavy box and the stairs): Do you have any ideas?
Sheldon: Yes, but they all involve a Green Lantern and a Power Ring.
Sheldon: Explain to me an organizational system where a tray of flatware on a couch is valid.
Howard (to Leonard, after a round of Dance Dance Revolution): Grab a napkin, homey, you just got served.
Leonard: That's fine, you win. (walks away)
Howard (to Sheldon): What's his problem?
Sheldon: His imaginary girlfriend broke up with him.
Howard: Been there!
Penny: Yes, I know men can't fly.
Sheldon: No, no let's assume that they can. Lois Lane is falling, accelerating at an initial rate of 32ft per second, per second. Superman swoops down to save her by reaching out two arms of steel. Ms. Lane, who is now traveling at approximately 120 miles per hour, hits them, and is immediately sliced into three. equal pieces.
Sheldon: Ah, gravity - thou art a heartless bitch.
Penny: And what kind of doctor removes shoes from asses?
Sheldon: If you have time to lean you have time to clean.
Leonard: You're going march yourself over there right now and apologize (to Penny)!
Sheldon: Pfffft.
Leonard: What's funny?
Sheldon: Wasn't sarcasm?
Leonard: No!
Sheldon: Uuuuuuh. Boy, you are all over the place this morning.
Sheldon: (Going apologize to Penny) I have a masters and two PhDs. I should not have to do this.