Kilmer's a very understated actor, but when you look at things he does to prep for a role, or small things he adds that aren't scripted or directorial decisions, but self-generated, you can appreciate that he was the youngest student ever accepted to Julliard and that he, you know, studied. And, has innovated since then.
Bale is a serious actor. He's a good actor. But his range seems, at this point, limited to how much muscle he can gain or weight he can lose, with his most memorable moments in flicks being when he's over-emoting or under-emoting. I'm not underselling him, or being negative there; I think there's incredible frisson in those skills, in that niche and range, and he works it. He's a better actor than George Clooney, and I like seeing Clooney in movies, too.