Lets see, First of all, i think that Michael Keaton is a great actor. he is good in comedy movies, and he is good in drama movies. I like almost all his work beasides the batman movies. He is a great and talented actor.
But, lets go to the batman movies. If they are doing an adaptation of the batman comics to screen, they should create all the crediblitiy that they can, but they didnt it. They should get an actor who looks Batman and Bruce Wayne , acts well and fit the part , Keaton didnt it. Not only he was phisichally the oppositte as batman and bruce wayne is, his Wayne was terrible. anything to do with the comic character. His wayne was a goofy and insecure idiot, insecure with women and absteminded. Come on, even he couldnt rememember some rooms in his own house. That was stupid. We want the cool play boy that bruce is in the comics and they bring us an absurd Chris Reeve's clark kent impersonator. Keaton sucked in the batman movies so bad that it was a total nightmare for the batman fans. Plus, the guy was a terrible fighter and slow as hell. His only merit was his voice change from wayne to batman, noting more.
About the other batmans, Kilmer was ok specially as Bruce, Clooney sucked as bad as keaton because he was only playing himself and playing doug ross from the I.E.R. tv show in stead of batman or bruce wayne and Bale IS batman and IS bruce wayne.