I went for Clooney on both. I honestly think he was a good Bruce Wayne because he has the right looks and charm to pull it off. I went with him as Batman due to the other options not being good ones. I admit B&R is a terrible, terrible movie and Clooney was given nothing to work with but that's not his fault. I think he did the "best" he could with the material. *No one* could have made the jokes in that movie work.
Why not Keaton for either role? When I think of Bruce Wayne I think of a handsome playboy (m)billionare. Not some pudgy middle-aged man which is why him as Batman doesn't work either. The rigid rubber muscles on the suit being a big sticking point.
Val Kilmer? I'm pretty sure he never made it into the actual movie. What we see in the movie is just one of those stand-in cut outs they use before inserting digital effects. They just ran out of money and were never able to insert Kilmer into the scenes and left the place holder there and thought no one would notice. We didn't.
Which leaves us with Bale. He does the handsome playboy Bruce Wayne good but almost too far into it. Bruce Wayne is still supposed to be somewhat cognizant of his surroundings and a capable businessman not a rich trust-fund idiot "crashing his car because he's trying to beat a light." As for his Batman...