3. Justice League Dark
I may be jumping the gun here when I say that Justice League Dark is stuck in development hell, since the project, which is being developed by Guillermo del Toro, was only announced last year. However, the team consists of characters who've had a difficult time getting their own films (Deadman, I'm looking at you), and del Toro has an unfortunate track record when it comes to announcing films that never get made. Justice League Dark will focus on a superhero team consisting of DC's lesser-known, more supernatural characters, including John Constantine, Zatanna, Deadman, Swamp Thing, The Spectre, and Etrigan the Demon. The team handles situations that aren't quite in the Justice League's wheelhouse, and offer a glimpse into a side of the DCU we haven't seen before. With WB currently working on launching a cinematic universe of their own, and a Justice League film most likely in development, it's unlikely that the studio would move this film into production first. A JLA film is in higher demand and will undoubtedly be the bigger cash cow, so a project like this, as unique and exciting as it may be, will likely get pushed aside until things start running a bit more smoothly.