Nightwing seems like a natural.

DC's Adam Strange would make a cool animated film.

Hawkman wouldn't be too hard to do with today's special effects. Or a Spectre film, with David Caruso as Jim Corrigan.

As for indie stuff, Bone and Akiko would make great animated flicks.

And since he's working in film now anyway, I'd love to see James Robinson bring Leave It To Chance to the big screen.