1. The Searchers, John Ford-High Noon and The Searchers are usually what most film scholars will tell you are the two greatest Westerns ever made. The Searchers had an outrageously low ranking in the 1998 list of 96, but in the 2007 list, The Searchers skyrocketed up to somewhere between 10 and 20 (if I were to go check, than I might see more results than I want to). The Searchers is the seminal moment in John Ford's career and was John Wayne's richest character, both the two main icons of the film Western. It's also the only Western that some people in the film community cite as the greatest American film ever, period.
2. High Noon, Fred Zimmerman-The other Western that's truly an American classic. It's casting was perfect, it has the most tightly coiled narrative and introduced a number of innovations: The theme music contained an opening song, the film moving in real time, etc. It also had political subtext and the people behind the movie are rewarded with bravery, in retrospect
3. Stagecoach, John Ford-If The Searchers was the apex of Ford and Wayne's career, it all started with Stagecoach which revolutionized the Western by introducing both of them to the big stage. Stagecoach is a masterfully done tale that's admired and next to Searchers and High Noon, I'll bet it's the only film that most people in the film industry agree deserves to be included on the pantheon of classics.
4. Wild Bunch, Sam Peckinpaugh-Wild Bunch revolutionized the use of violence in movies and has a terrific narrative. It changed the nature of Westerns toward outlaws vs lawmen rather than on conflicts within a town that a hero would have to chose the right side to be on. It's also a very fun movie, but I most believe it's going to be #4 simply because it was ranked pretty high on both AFI lists, previously.
5. Shane, George Stephens-I find it to be kind of a corny film, but the experts consider it in the realm of classics and it has been voted both times. Jack Palance from City Slickers got an academy award for it. Perhaps, they view it as the definitive Western from the point of view of a child, since the star of the film besides Alan Ladd's Shane character is really a 12-year old kid.
6. Unforgiven, Clint Eastwood-Unforgiven might rank closer to 10 or 12 on a list of Westerns among film scholars who are experts specifically on the evolution of the Western, except for the fact that Clint Eastwood is so hot right now, so retroactively his film career enjoys a big bump. It is truly a good film but it would be an oversight to label it as the first retrospective Western that demythified what came before it. (That might be McCabe and Mrs Miller)
7. Butch Cassidy and the Sundance Kidd, George Roy Hill-Kind of like the rock stars of the Western, Paul Newman and Robert Redford's characters defined the Western heroes as supercool. But else why would Butch Cassidy and the Sundance Kidd be selected at #7? Redford and Newman are both still alive and command a lot of respect, and this film made the top 100 twice.
8. Rio Bravo, Howard Hawks-All the John Ford films She Wore a Yellow Ribbon, How the West Was Won, My Darling Clementine, and Man Who Shot Liberty Valance will open the way to some sneakers to make it through do to vote splitting. With the help of Quentin Tarantino's tireless promotion (it's his favorite film) and the crowd that enjoys a light-hearted Western that can make them laugh, fawn over the romantic interests, and root for sympathetic characters plus the Dean Martin fan contingent, Rio Bravo should be able to seperate itself from the rest of the pack nicely.
9. How the West Was Won, John Ford-Is this John Ford's 3rd best film? Not necessarily, but it's his most grandiose title and some voters (like myself at first glance) might confuse this with Once Upon a Time in the West and vote for it. Plus, I hear it has Debbie Reynolds in it, who is still alive and actively pimping her career.
10. McCabe & Mrs. Miller, Rob Altman-I seriously think that whether McCabe & Mrs. Miller makes this list will serve as a litmus test to whether the film community truly feels that Altman's work was great enough to be considered among the classics. Altman had an extra entry in the top 100 last year with the addition of 1975's Nashville, and I know there are a lot of other good films after the first 9 such as Duel in the Sun, Red River, Man Who Shot Liberty Valance, and My Darling Clementine but are any of them as definitive as this film (and like I said, there's vote splitting to worry about)? McCabe & Mrs. Miller demythified the genre significantly more than anyone else, and was such an interesting take on existing genre conventions.