Leonard: What ya doin' there? Working on a new plan to catch the Road Runner?

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.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

Penny: The Flash shirt is what? Because you're gonna run really fast?
Sheldon: No, the Flash shirt is because it's Friday. But it's nice when things work out.

Sheldon: At my age, do you know how I'm statistically most likely to die?
Leonard: At the hands of your room mate?
Sheldon: An accident.
Leonard: That's how I'm going to make it look.

Penny: You wanna turn yourself into some sort of robot?
Sheldon: Essentially, yes.
Penny: Okay, here's my question: Didn't you already do that?