I like Hugo Strange. He's a villain I completely relate to especial in Matt Wagner's Monster Men.
Strange is a man with a chip on his shoulder. He feels that he should be superior but somehow ends up inferior due to whatever perceived flaws he has (which is no doubt exacerbated by the world we live in where LOOKS matters more than ability) and strives to attain this perfection.
He's like a kid growing up looking at muscle men on the covers of body building magazines. He wants to be like them so badly, and he works hard at it, looks down on EVERYONE who doesn't believe in what he is doing and like all body builders and athletes have bouts of self-loathe and depression on his journey.
Except the only difference is Strange doesn't want to be a body builder, he wants to be Batman, who is in his eyes the perfect example of an Alpha Human being. A marriage of keen intellect and physical attributes. And he gets laid regularly too. So yeah, I can completely understand WHY Strange is so damn obsessive.
There have been trends of "Dark Batmen", like Jason Todd,Hush, the Wraith, Prometheus or Jean-Paul Valley or that weird Batmen storyline cooked up by Morrison back in R.I.P, but most of them don't really get under the skin or the psyche of Batman quite like Hugo Strange does.
And no, I'm not just saying this because he appeared in Arkham City. I've always held Strange in regard as an under-used Batvillain, joking that he is Batman's biggest obsessive fanboy.