Not so much famous for Clint Eastwood's performance, as for the extraordinary soundtrack by Ennio Morricone, is the spaghetti Western thriller The Good, The Bad and The Ugly.
One hundred and seventy-nine minutes of it (recent extended version). Man, it went on, and on...dragged a bit here and there, but fascinating nonetheless.
I found Lee Van Cleef as Angel Eyes an utterly compelling character.
Quentin Tarantino has apparently described it as "the best-directed film of all time" - that is interesting coming from him.