The wait is finally over: Alan Moore's Watchmen, the 'unfilmable' graphic novel masterpiece, has been turned into a film by none other than 300's Zack Snyder. But before your head starts to spin from the slow-mo, remind yourself how we got to this stage. There was Terry Gilliam (failed - Baron Munchausen did nothing for his financial credibility), Darren Aronofsky (failed - he wanted to make The Fountain, Lord knows why), and even Paul Greengrass (failed - Paramount didn't have the monies).