5) Hush
Hush was a divisive story at the time of release, and even now fans still debate whether it really should be considered a modern classic. Whatever the case may be in that respect, there’s no denying the fact that Hush as a character most definitely has a lot of cinematic potential, as do elements of the storyline itself.
The plot saw Batman square off with almost all of his iconic rogues gallery as he attempted to find out the truth behind a mysterious new foe in Gotham City. The budget would obviously have to be pretty huge to include all of his villains, but do it over a trilogy and it would be epic.
Hush himself was revealed to be Thomas Elliot, a childhood friend of Bruce Wayne who spent decades plotting his revenge on the Wayne family over the fact that Bruce’s father saved his mother’s life after a car accident. It turns out that Thomas caused that accident as he wanted to get his hands on his inheritance early, and for whatever reason, he ended up blaming Bruce for his plot failing.
A movie could really delve even deeper into that and make Hush significantly darker and more complex as a villain, and he should definitely be considered for at least one of these Batman movies.