Usual Suspects - best film of all time.
One Flew Over the Cuckoos Nest.
Love Jack Nicholson - just watched OFOTCN recently. Not seen Usual Suspects yet. Went for more recent film instead 'Sicario' - enjoyed it.
What genre are you thinking? Agree on usual suspects and ofotcn, 2 of my all time favs. Shutter island, the silence of the lambs, gran torino, green mile are more epics. Should have a movie thread in the dump. If in doubt, just have a gander around the imdb top 250.