Unforgiven was good. Personally, I liked Lonesome Dove. Of course, I can't help but to like Tombstone.
But on the not-so-realistic side, I still enjoy all the John Wayne flicks: Stagecoach, The Searchers, The Man Who Shot Liberty Vallance, Hondo, McClintock, Rio Bravo, Rio Lobo, Rio Grande, El Dorado, Big Jake, Cahill: U.S. Marshal, True Grit, The Shootist. You just can't beat a good John Wayne western. I especially enjoy seeing him with the same rig throughout most of his movies. The only thing I can't stand is seeing all those Buscadero rigs on the other actors.