I like Batman because for some odd reason, he scares the crap out of the bad guys... even when he never kills them.
Actually... that and the fact that I think he's a rather deep character. I mean, Bruce Wayne is his disguise, and Batman is who he is. Ya know? To me, that's kind of cool.
Not like Clark Kent dressing up like Superman. Peter Parker becoming Spider-man. No, Batman takes off the mask to become Bruce Wayne. I like that.
That, and Frank Miller's Dark Knight Returns and Year One are really, really good, and The Long Halloween might just be my favorite comic book story ever.