For a while now there has been so much competition from both of the worlds greatest Batmans as far as opinions go.
When Keaton played Batman, He explored the emotional side that people weren't used to.He gave us a Batman that was as much in depth as his alter ego Bruce Wayne was.I honestly preferred Keaton's because he wasn't afraid to do what was necessary unlike Bale.
As for Bale...He gave us the Batman that people were so thirsty for after the Garbage of the Schumacher films literally drained us. He was so mechanical in his ways of fighting crime and was as relentless as the people he crumbled night after night. Bale gave us a badass batman while keeping the mechanical and emotional separate. Which I think was a good strategy to playing Batman