I've never been a fan of the Western genre, but I found myself enjoying this one. This is not your typical Hollywood Western. It cuts out pretty much every romantic vision of the American west that Hollywood has ever portrayed and just presents a fascinating bare bones account of one of the frontier's greatest heroes. Rather than focusing totally on the OK Corral, there is an emphasis on the events prior to Tombstone that molded Wyatt Earp.
This is one of the few Western movies I've seen where you get a feel for how it actually might have been to live in that time. Instead of the usual Hollywood fluff, you get something much different. There are still scenes with stagecoaches and saloons, but they don't seem as romanticized as in other Westerns. And you also get other non-Hollywood visions of the West, such as scenes with buffalo being slaughtered and skinned.
Wyatt Earp himself is portrayed as a very powerful individual who, while fighting on the side of the law, could also be cold-hearted, cruel, and excessively violent at times. Attributes necessary for survival as a lawman.
Costner is fantastic as Wyatt Earp, with one minor complaint. He's got the attitude, posture and look down pat. It's just that I think his voice is a bit too nasally to carry the power that Wyatt Earp must have had whenever he spoke. As for the other actors, they are all outstanding with Dennis Quaid in particular turning in a great performance as Doc Halladay.
A lot of people have commented on this movie and Tombstone. Personally, I enjoyed both, but the difference is that when I watch Tombstone, I feel like I just watched an entertaining story, whereas when I watch Wyatt Earp I feel like I just saw a piece of history. Overall, an excellent and very under-appreciated movie.