Some of my favorites have already been mentioned -- Obi-Wan's observation of Mos Eisley from Star Wars, Inigo Montoya's line from Princess Bride.
How about this from Empire Strikes Back, when the Empire is invading the rebel base on Hoth --
Han: "We don't have time to discuss this in committee!"
Leia: "I am NOT a committee!"
And this reminds me of a similar quote from Phantom Menace --
Amidala: "I was not elected to watch my people suffer and die while you discuss this invasion in a committee!"
From Apollo 13 -- "Failure is not an option."
From We Were Soldiers -- "I can't promise you that I will bring you all home alive. But this I swear... when we go into battle, I will be the first to step on the field and I will be the last to step off. And I will leave no one behind... dead or alive. We will all come home together."
From Young Frankenstein: "What knockers!" "Oh, thank you, Doctor." and "Igor, help me with the bags" "Okay, you get the blonde and I'll get the one in the turban."
