A repost but a much more detailed idea of mine. The first was an introduction to my Harley Quinn, this is a fake poster of mine for a fake future film "Arkham Asylum". Some of the best criminals in the DC universe would be shown in this film, and I chose my own cast this time. Here are my actors and casts:

Brittany Murphy/Harley Quinn: shes cute and can act bat shit crazy. Watch Spun-nuff said.

Naomi Watts/Poison Ivy: I don't want Pamela Isley to be fanboy candy if in a movie, she'd be a biologist and pharmacist in Arkham and best friend of Harley since college. She'd be cold and more intelligent, and a lesbian. But that wouldnt be said. anyway she'd be developing new drugs on the patients and would be exposed herself to deadly chemicals. She'd become obsessed with toxicology and plant life, using them against people.

Johnny Depp/The Joker: No I'm kidding. I just wanted to fill it. I would have put ledger up there but it would have looked eerie.

Kate Beckinsale/Catwoman: she said she expressed interest. Selina wouldn't be in Arkham, but she'd be the first and prominent criminal batman is faced with. Like in Batman Returns.

Cillian Murphy/Scarecrow: he'd be used in a small role, his fear drug and psychiatry being very useful.

Joshua Harto/The Riddler: Dunno....some people speculated he could be the Riddler, since he knew who batman was. Not a large role....

James Callis/The Black Mask: thats right, the battlestar galactica badass would be playing black mask, which a lot of fans want to be in the next movie. hes crazy as FUCK, but much darker than the joker, and could be a major aspect of the film, being the MAIN criminal. once again, idk, this is all just wishing.