Well there's Lex Luthor, when written well he's more or less a monster-champion of humanity whose greatest ambition is to save us from the supes, but then he's still bound by conventions that DC isn't willing to break, conventions most fans probably don't even want them to break.
Another little thing that bugs me that I'd like to take on? Characters never seem to learn or grow, sometimes even in the context of a single creative team's run. Street level thugs I can kind of understand, but mastermind criminals capable of building time machines don't learn from there mistakes? Or heroes who never become desensitized to death, or at least let it really get to them.
I think I would be most inclined to model my altruistic characters after desensitized, disgusted police officers who have to respond to the same trailer park domestic abuse call every night and want to help but can't because Darleen keeps taking her boyfriend(s) back, or EMS dealing with fatal DUI related crashes. They might get to be shocked, surprised and abhorred by the visceral nature of the game the first couple of times they're out, but after that they should become just as frazzled and exhausted as the guy at work who just told me about having to deal with a woman who let her 3 y/o daughter drink bleach.
Which leads me to another point. I can suspend disbelief long enough to accept a walking man made of mud or a primordial planet eater, but not that someone with so much power wouldn't eventually snap and just start killing their villains. Batman sometimes makes sense, he can't bring himself to kill because of his childhood trauma, it's actually a symptom of mental illness. Which makes crazy Batman, to me, better than wholesome Holy Rusted Metal, Batman! You could even say that Spider-Man is a self-loathing guilt addict who wants to be punished for what happened to Uncle Ben and Stacy which is why he keeps letting murderers return to jail so they can escape to kill again in order for him to maintain his cycle of guilt and pain. The other ones that are more sane and pull this shit? Not so awesome.
See, this is why I would be a terrible writer; people don't even like watching the news because it's too depressing, let alone the shit I want to write about for entertainment purposes.
