Leonard: What about tiresome lunatic with a bad haircut? Has he called yet?

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Leonard: My point is, while you're spending all this time on your own, building computers or practicing your cello, what you're really doing is becoming interesting. When people finally do notice you, they're gonna find someone a lot cooler than they thought. And for those of you that were popular in high school, it's over, sorry. Thank you. Congratulations.

Leonard: [to a "smiling" Sheldon] We're here to see Koothrappali, not kill Batman.

Sheldon: Until next week, this is Professor Proton saying, 01000010 01111001 01100101. That's "Bye" in ASCII binary, or good-binary.

Sheldon: Well, it should be a scientist I respect. You know, someone with a pleasing voice and symmetrical facial features.
Bernadette: Is he talking about himself?
Penny: If he's talking, he's talking about himself.

Amy: Well, what was wrong with it? You know, did you find it borderline psychotic? I mean, I liked that about it, but you guys discuss.