What would you choose to make a film about?

I've always wanted to write screenplays but have never even remotely tried. I think I'd like to write a screenplay about the lives of the pre-Raphaelites, and one about the life of poet Byron Herbert Reece (whose story interests me more than his poetry and less than it used to), a documentary about folk art in the Southeast, and one about Sufism in this country, dealing partly with how Coleman Barks and Robert Bly have helped to make people more aware of it and of the poetry connected to it. I've had other ideas too but can't think of them just now. The pre-Raphaelites were a fascinating group of people, and I'm surprised no one has made a film about them. I admit I think Johnny Depp reminds me of Dante Gabriel Rossetti. Oh, and I'd like to see an expose of sorts made about urban sprawl in one specific rural area, let's say north Georgia, and how it's impacted the landscape and the culture. I don't think people realize how sprawl changes and damages the particularities and singularities of an area's cultures much more radically and quickly than would ordinarily happen. Things like art, architecture, foodways, and music get hurt by the breakneck construction of new cookie-cutter developments and the resultant eradication of the uniqueness and strangenesses of an area. 
This is a good blog question and it's got me in a listmaking mood, so expect more later perhaps.

artwork courtesy of Billy Roper