Justice League Mortal

If this superhero film was made, DC would have beaten Marvel in bringing the first ensemble cast for a major comic book movie.

George Miller (who directed the awesome Mad Max: Fury Road) was already hired to helm Justice League Mortal, while the cast was already in place: Armie Hammer (Batman), D.J. Cotrona (Superman), Megan Gale (Wonder Woman), Adam Brody (The Flash), Common (Green Lantern), Santiago Cabrera (Aquaman), and Hugh Keays-Byrne (Martian Manhunter). The villain was supposed to be Maxwell Lord and was set to be portrayed by Jay Baruchel.

What happened? It's everybody's guess as to why the project failed to be launched. But a documentary about this failed superhero project is almost green-light by Warner Bros.