Batman for me. He doesn't actually have any super powers (does he?) and he's got a dark side to him. Superman is just too goody goody. Batman might do anything but Superman is limited by his moral code to the point where he's very predictable.
If I was a writer, I'd much rather write for Batman than Superman.
Superman, He could spin rapidly around the Earth and go back in time and stop the Joker Killing Batmans parents thus eliminating the creation of the Bat and still being within Supermans ethical code...... Ipso Facto.
It has to be Batman . Remeber he is a detective rather than a superhero.
The problem with Superman was he became too strong and invincible.
Stages of the comics became too comical and occasionally farcical as they had to create new weaknesses to bring him down to earth.
Batman is much more vunerable and therefore has a much better backstory and much more interesting problems.
'There is no future for e-books, because they are not books. E-books smell like burned fuel.' Ray Bradbury (RIP)
Batman...he's got a better costume...Better disguise (glasses? Yes, cunning, superman)...And he does everything without the help of superpowers. *coughthefactthathe'sinheritedloadsofmoneyisirrelevantcough*
If Superman's acquired a dark side recently, it's probably in respose to comics like Batman who've had one for ages.