Sheldon: I think that you have as much of a chance of having a sexual relationship with Penny as the Hubble telescope does of discovering at the center of every black hole is a little man with a flashlight searching for a circuit breaker.

Howard: Sheldon, if you were a robot and I knew and you didn't, would you want me to tell you?
Sheldon: That depends. When I learn that I'm a robot, will I be able to handle it?
Howard: Maybe, although the history of science fiction is not on your side.

Wolowitz: Love is not a sprint, it's a marathon, a relentless pursuit that only ends when she falls into your arms - or hits you with the pepper spray.

Sheldon: I do feel obligated to point out to you that she did not reject you, you did not ask her out.
Leonard: You're right. I didn't ask her out. I should ask her out.
Sheldon: No! No that was not my point. My point was don't buy a cat.
Leonard: No, but you're right, I should march over there and ask her out.
Sheldon: Oh, goody! We're getting a cat.

Sheldon: Penny for your thoughts?

Sheldon: (to Leonard, who has decided to give up on Penny) Well, at least now you can retrieve the black box from the twisted, smoldering wreckage that was once your fantasy of dating her and analyze the data so you don't crash into Geek Mountain again.

Sheldon: Score 1 for liquor and poor judgement.

Raj: He's selling the Sword of Azeroth on eBay.
Leonard: You betrayed us for money? Who are you?
Sheldon: I'm a rogue Night Elf. Don't you people read character descriptions?

Raj: Tonight I spice my mead with goblin blood.

Leonard: I was thinking more of a biosocial exploration with a neurochemical overlay.
Leslie: Wait, are you asking me out?

Sheldon: There's always a chance that alcohol and poor judgment on her part may lead to a wonderful evening.

Sheldon: Is the sex starting now?
Leonard: I'm having a panic attack.
Sheldon: Oh, okay. Well then, calm down!

Wolowitz: I am the sword master!

Leonard: Raj, no, it's a trap. They're flanking us!
Raj: Oooh, he's got me.
Howard: Sheldon, he's got Raj. Use your sleep spell. Sheldon! Sheldon!
Sheldon: I've got the Sword of Azeroth!
Leonard: Forget the sword, Sheldon, help Raj.
Sheldon: There is no more Sheldon. I am the Swordmaster!

Leonard: Great. Did we say a time?
Penny: Six thirty.
Leonard: And that's still good for you?
Penny: It's fine.
Leonard: Cos it's not carved in stone.
Penny: No, six thirtys great.
Leonard: I'll get my chisel.
Penny: Why?
Leonard: To ... carve the ... okay, I'll see you six thirty.