3) Hellboy 3
Guillermo del Toro is the king of films stuck in development hell, with many a project suspended in limbo. One of these is unfortunately the long awaited third movie in his Hellboy series.
Though the film have an ardent cult fanbase, the story of an anti-hero demon just doesn’t appeal to mainstream audiences like Spider-Man or Batman, and so, the Hellboy films have never been big money-makers. As such, though del Toro and star Ron Perlman are very keen to do a third outing, no studio is currently willing to supply the cash.
Sadly, it’s looking increasingly likely that this one will only happen when hell freezes over.