Here's my idea of what I would like to see happen in the next Batman movie. The plot would be the story of how Harleen Quinzel became Harley Quinn. We all know how Batman and Joker became who they are. But with this we can see how the Joker corrupted Harleen Quinzel and show how she fell in love with him and became his sidekick, as well as one of the main villains of Batman lore. This can show Batman's side of trying to help her and make her understand that the Joker is not how she sees him.
This would be a live action movie and it would need to be rated R, because I think this should be a Batman movie that is as close to the comic books as possible. And it will have Barbara Gordon but not Batgirl (save it for the sequel).
So here are my casting ideas for the movie...
JUNO TEMPLE as HARLEEN QUINZEL / HARLEY QUINN
AARON PAUL as THE JOKER
KEVIN PORTER as BRUCE WAYNE / BATMAN
PATRICK STEWART as ALFRED PENNYWORTH
BRYAN CRANSTON as COMMISSIONER GORDON
EMMA STONE as BARBARA GORDON
BILLY UNGER as DICK GRAYSON / ROBIN
Now I would have at least one guess star / cameo for the movie. No, no, it would not be Superman. I mean that's what people would think, but I would pick someone that I have always wished to be in a DC movie live action...
BENEDICT CUMBERBATCH as VIC SAGE / THE QUESTION
Now you're asking, who should direct this movie? I thought long and hard about this but came up with one person... Quentin Tarantino. "Why?" you may ask. Well, I mean come on. He has done films like Kill Bill, Django Unchained, Inglorious Basterds, Reservoir Dogs... need I go on? Plus, he would take a fresh look at it and make it his own, like Christopher Nolan did, while still sticking to the comic books.
So one day they will make this or something like this, I hope. All in all, this is my movie idea.