Batman: The Dark Knight Returns

If any comic has a claim to have truly reinvigorated the genre, then The Dark Knight Returns by Frank Miller--known also for his excellent Sin City series and his superb rendering of the blind superhero Daredevil--is probably the top contender. Batman represented all that was wrong in comics and Miller set himself a tough task taking on the camp crusader and turning this laughable, innocuous children's cartoon character into a hero for our times. The great Alan Moore (V for Vendetta, Swamp Thing, the arguably peerless Watchmen) argued that only someone of Miller's stature could have done this. Batman is a character known well beyond the confines of the comic world (as are his retinue) and so reinventing him, while keeping his limiting core essentials intact, was a huge task.