Only one will claim the night.

I won't lie: I was one of many comic fans who did not want Michael Keaton to portray Batman. I just didn't see it. That totally changed when I was lucky enough to see an advanced screening of Tim Burton's break-through movie at NYC's Ziegfeld theatre in June of 1989. While the film does have it's flaws, the indelible culture impact this movie had still resonates today. 30 years ago, you could go into any store and find Batman merchandise. 30 years later, you can still go to any store and find Batman merchandise.
I had hoped to see more action in the film, but Burton's choice of Keaton was brilliant. The entire scenario of the film was crazy: a guy dressed like a giant bat, a killer clown who poisoned people through cosmetics, overwhelming architecture that looked as if it would devour the citizens of Gotham City. But Burton saw Michael Keaton as the only actor who could dress up like Dracula so he could go out at night to beat the shit out of criminals. And he was right. Keaton's performance is 100% believable. Despite Jack Nicholson getting most of the accolades for the film's success, Keaton supports the massive weight of the film with his credible approach. Having recently viewed the film again after not seeing it for many years, I find that fact much clearer than I did in 1989. If you don't agree with that here's a closing point. Look at any Batman project of the past three decades. Whether it's live-action or animated, 98% of the time, every actor who has portrayed Batman is doing an impression of Michael Keaton. That's how good he is in the part.