as much as i love the Nolan/Bale films, Burton & Keaton together make my favorite Batman!
his was a Batman that was just f'ed up in the head...like weasel said,it seems when he's "Bruce Wayne". he's just PLAYING normal,or what he thinks normal should be, but the reality of his being Batman starts to creep past the Bruce Wayne persona he puts out there,to where he starts to become Batman all the time...once he starts his rivalry with the Joker,that's all that matters to him...hell,he doesn't even want to be bothered with Kim friggin Basinger til Alfred keeps bugging him about her,and even then it ends badly with the Joker intruding and Batman pushing past "Bruce Wayne" again...
this continues onto Batman Returns,where he's sullen,living by himself in the Manor,having pushed Vickie away for good due to not being able to seperate himself from Batman ,and even when he's out as "Bruce Wayne" ,it seems like he's still in Batman mode,confronting Shreck and trying to tie him to the Red Triangle Circus Gang....only when he meets Selina,literally his soulmate,does the REAL Bruce Wayne start to emerge again,as he grows to care for and love her,perhaps subconsciously at first,as here's someone as dark,hurt,and f'ed in the head as he is...
Keaton's Batman is a tortured,hurt soul , who's severe moment of pain changed his psyche forever to one where he needs to strike back at criminals in a supernatural form,a 6 foot black Bat....and he pulls it off completely and believably....
Kilmer was decent as a Batman starting to become Bruce Wayne,but he didn't have that menacing feeling at all.... Clooney was just a bachelor playing with toys.... Bale is good,great even,but he just feels like a man with a mission,a soldier who's tackling the criminals of Gotham....Keaton was MENACING,and scary,and could make you believe he'd have criminals crapping their pants,as he just looked and acted like someone not in their right mind...NO other Batman actor has gotten the psychological issues that reside in Wayne's head down right other than Keaton....