For me, 1989 Batman will always be my favorite, by far. The second Burton outing was just to big of a mess. The Schumaker films were all but unwatchable.
I enjoyed Batman Begins, but thought they spent way too much time on history and backstory. I don't care to know how or why he learned martial arts or the entire story behind the batmobile. I much prefer the darkness and mystery of Batman89. Which brings me to my only serious criticism of the Nolan films; the high-contrast cinematography. I really don't like how well-lit and sharp everything is. For me, that literal removal of the darkness also takes away the character's darkness. Dark Knight seems even more well-lit\high-contrast than Begins.
I've been a Batman nerd since the 60s. When I was a little kid, I never missed Batman on TV every week. I had the comic books, made mt own capes, etc. For me, when Batman89 was released, it was what Batman had always been in my imagination. To me, it was perfect - Keaton, his portrayal of Wayne, the Batcave, the darkness, the mystery - all of it. Not to mention, the coolest Batmobile there has ever been.
Unless a bunch of people want to go after work one night, I'll probably wait for Dark Knight on cable.