DC One Million takes everything that made all the previous crossovers on this list - time-travelling, crazy adventures, implications for the characters involved, the involvement of Grant Morrison, space - and mashes them up into one amazing, strange, and entertaining story that leaves all of its peers in the dust. Taking place in the year 85,271 AD (the time when, theoretically, DC's main titles would have reached their millionth issues), the crossover did have its weak points - especially the cheesy covers that aim for "cutting edge" but land more in "cheesy nineties CGI" - it's mainly a crazy romp that gives a peek into the far-flung future of your favourite superheroes. In the world of DC One Million, there are entire cultures based around the likes of Batman and the Flash, meaning they have not one but a whole host of "legacy" characters that have picked up their mantle when they inevitably fell prey to their human morality. One character doesn't suffer from that problem, though, as Superman finds to his surprise that he is still alive, tens of thousands of years into the future. Oh yeah, and the reason the Justice League of our time are meeting their future counterparts is because Vandal Savage, who is an immortal cave man, and Supernova, the living sun, are threatening to destroy all of history itself. It's all the sort of thing that would sound trite and cliche if you tried to do it nowadays - in fact that has been some people's reactions to current DC crossover Future's End - but at the time, One Million was everything good about comic books rolled into one. A hopeful look towards humanity's future, heroes teaming up to face impossible odds, colourful costumes, and a key role for the Martian Manhunter. Everyone's a winner!
Tom Baker is the Comics Editor at WhatCulture! He's heard all the Doctor Who jokes, but not many about Randall and Hopkirk. He also blogs at http://communibearsilostate.wordpress.com/