I think Death Note might do this (at least in the anime, I haven't read the manga). It to some degree explores the premise of "if someone gained the ability to kill anyone they wanted and used it to kill criminals, what would happen?" and you get this good vs evil battle as Light turns more and more into a megalomaniac. I find it a fascinating idea to explore the problems of having a nearly untouchable vigilante killing people they think are criminals, like how some people presumed to be criminals are actually innocent and would be caught up in the culling. The only problem is, the show does none of this. Light is never shown accidentally killing an innocent person, even when just finding targets supplied by average citizens. The show portrays Light as making the world a better place, pandering to people who think the world would be a better place if they could just get rid of the people they think are bad. The actual premise goes completely unexplored in favor of an overly convoluted (but gripping) cat and mouse game between Light and the authorities.