If you like that sort of thing, I would recommend The Watchmen by Alan Moore. Its for mature readers, but its a masterpiece in that field.
Folks, I can't POSSIBLY
agree more. The Watchmen
is, far and away, the single best graphic novel I've ever come across, bar none. Even if you're not into graphic novels, you ought to read it just for the story alone.
p.s. While digging for an image to put here, I just found out that they are turning this into a movie. The director of the soon to be released 300 is set to direct.
I hope it's true this time, since there have been rumors of this becoming a movie for well over a decade now. And BTW, the director of 300
is the same one who directed Sin City.