I'd like to see Barry as the Flash. I have to admit, I'm unimaginative, and I'd pic someone like Neil Patrick Harris or Joseph Gordon Levitt to play Barry. Storyline wise, I think I'd like to see them stick close to his origin story, with someone like Mirror Master as the villain. Altho, I'd rework Mirror Master a bit, give him a bit more of an edge. If Mark Strong hadn't been Sinestro, I'd nominate him as Mirror Master, instead, I think I'd pick someone like Jason Isaacs.
I'd love to see someone like Guy Ritchie direct it.
What'd really be cool, hide Black Flash (Death) in a couple crowd scenes, through out two movies, then have Barry face Black Flash in the third movie.
Y'know, I've been thinking about something. Barry Allen was a forensic scientist before the accident, right? It's like most writers seem to forget that he's a scientist.