Sergio Leone's The Good, the Bad and the Ugly is the third installment in an unofficial trilogy of spaghetti westerns (the others being A Fistful of Dollars and For a Few Dollars More). All three star Clint Eastwood as "The man with no name," and are highly recommended.
Rio Bravo I hear good and bad of--it's a Howard Hawks-directed picture with John Wayne, so can't be all that bad. Mad Max sounds and looks horrible, but one of those that gets cult followings.
Mick