Sheldon: Wait, put this in the bathroom.
Leonard: What for?
Sheldon: I need to measure my fluid intake and output to make sure my kidneys aren't shutting down.
Leonard: I mix pancake batter in this!
Sheldon: No, that measuring cup has always been for urine.
Leonard: You had time to make a label for everything in this apartment, including the label maker, but you didn't have ten seconds to make a label that said "urine cup"?
Sheldon: It's right here on the bottom.
Leonard: Huh, I guess I owe the Betty Crocker Company a letter of apology.

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.

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.

Mrs. Wolowitz Howard, it's the phone.
Howard: I know it's the phone, Ma. I can hear the phone.
Mrs. Wolowitz Well who's calling at this ungodly hour?
Howard: I don't know.
Mrs. Wolowitz Well ask them why they're calling at this ungodly hour.
Howard: How can I ask them when I'm talking to you?

Sheldon: Checkmate.
Leonard: Oh, again?
Sheldon: Obviously, you're not suited for three dimensional chess. Perhaps three dimensional Candy Land would be more your speed.
Leonard: Just reset the board!
Sheldon: It must be humbling to suck on so many levels.

Mrs. Wolowitz: Howard it's the phone!
Howard: I know it's the phone ma! I hear the phone!
Mrs. Wolowitz: Who is calling at this ungodly hour?
Howard: I don't know!
Mrs. Wolowitz: Well ask them why are they calling at this ungodly hour!
Howard: How can I ask them when I'm talking to you?