I'm surprised Airplane didn't make the list but Jackie Brown and The Departed did. Both are good films but very very rarely hear people quote lines from them, whereas most people almost as a reflex to any question beginning with, "Surely you can't..." respond with "Don't call me Shirley." Doesn't it also have the highest rate of jokes in any film, 3 per minute or so?
Onto the choices at hand, and I'm gonna go with Terminator.
Despite Arnold's very limited dialogue in the first film, 3 words are synonymous with not only the franchise but him the person too, "I'll be back."
It's minimalistic but tells you everything about the character when coupled with his look. He scans the desk area robotically, takes a look at the guard then leans in to deliver his line. The fact it's a commonly used expression meant with no menace usually is completely turned around by the fact we know this guy is a terminator, that's his function, to terminate, and adds a chilling overtone to such a casual phrase.
Other great quotes from the series
"Come with me if you want to live."
"There's a storm coming in." "...I know."
"You're terminated fucker!"
"Sarah Connor?"
"His name is Connor. John Connor. Your son, Sarah, your unborn son." "Well at least now I know what to call him."
"Hasta la vista baby"
"What's wrong with your eyes?"
"I need a vacation"
"I need your clothes, your boots and your motorcycle"
etc