It's strange that the first time I saw Tombstone, I didn't like it. At this point, I can't imagine not enjoying a movie starring Kurt Russell, Val Kilmer, Bill Paxton, and Sam Elliot. And Powers Boothe! And so on. I think what I like the best about it is that it's not really ironic at all. Wyatt Earp is very, very angry and is out to kill people. The only character with a sense of humor about what's happening is Doc Holliday, and he's an enormous amount of fun while at the same time being a cold-blooded killer.
Incidentally, while I was watching the movie, I was aimlessly reading about the actual gunfight at the OK Corral on the internet (because nothing spices up a movie-going experience like research!) and my new favorite gunfight is the Gunfight at Hide Park. Essentially, you've got a saloon where three thugs shoot a guy who shot their friend, and then this kid named James Riley opens fire on the whole crowd. Riley kills four people and wounds three others. It looks like he was just firing randomly into the crowd, since he hit innocent bystanders. And here's the best part: after the shooting, he walked out of the saloon and was never seen again. Isn't that awesome?