greatest movie ever

hi, had this in wrong forum so will try again

like to hear what movies each of you would nominate as an outstanding work of art or just great entertainment.

let's do one each and see if we can't expand on this thread and keep it running for those boring moments when we arn't watching the stocks.

foreign movies are fine as well.

first movie i'd like to mention is "Old Boy" it's a korean movie. great story and acting. a number of realy excellent twists you just don't see coming.