The Poseidon Adventure (1972)
Ronald Neame's 1972 capsized ocean liner. Gene Hackman, Ernest Borgnine, Shelley Winters.
Gene Hackman looked like a man you would not notice, and built a career on it. Popeye Doyle in The French Connection is a bigot and a bully who happens to be right, and the film refuses to soften him. It won Hackman Best Actor.
The Conversation gives him the opposite: a surveillance expert so private he cannot be reached, and the final scene, in which he dismantles his own apartment looking for a bug, is one of the great images of paranoia.
He won Best Supporting Actor for Unforgiven, playing a sheriff whose brutality is entirely reasonable to himself. Little Bill is the most frightening thing in that film precisely because he thinks he is keeping order.
He retired in 2004 and turned to writing novels, declining to return despite regular offers.