Hi,
Very tough question, even for me, who is one that depends on the visuals that music gives me to figure out what I like to listen to and not listen to ... it's not about a song for me, it's about the emotional experience it shows me.
Some that deserve a film, or something visual:
Camel - Snow Goose
YES - Tales of Topographic Oceans. Would be very tough, but do'able.
Genesis - The Lamb Lies Down on Broadway. (And I think there was something for it, that was probably shelved when the album got totally trashed by the Led Zeppelin/Who fan'dom and kiss'dom of fans. And it caused the band to shelve the 4th side of the albums and put together something more "fan" friendly! There have been some attempts to do this, but the imagery was taken from the original pictures on the album, and not exactly well written as a story/movie for it to make sense, but the last part of the album takes away the complete story and ruins the movie ... like it has no meaning other than rock'n'roll ... and that is one of the saddest things EVER, that I have ever heard! Probably a fight with the record company, also, I bet.
ELP - Pictures at an Exhibition. This would be done nicely with a lot of museums and their work ... you could do this alone with the Louvre!
Carmen - Fandangos in Space. With director Carlos Saura, this would become another version of his film Carmen (1983) which was instead a story about the old dancing against the new dancing, and it made for a fantastic film. "You dance with your eyes, not your ass!". The whole of the 3 albums could be combined into one story, ending with "The Gypsies" , which are a part of the story of Carmen, although the opera and related stories tend to bring that part down. A bit racist perhaps, but something that is common in Europe.
Vangelis - Already has enough screen credits ... I don't think he needs any more, really.
Frank Zappa - Though it doesn't need it, and the orchestral version is excellent enough as it is, a funny redo of 200 Motels, would probably make more sense today, and show Frank's music better ... maybe one day, someone can find out how Mystery Roach and Donovan can end up in the same page ... and everyone go ... wtf?
Pink Floyd - If it EVER was possible, would like to see "Zabriskie Point" redone with all PF music, and tell Roger to shut up and stop putting words in Antonioni's mouth, that likely weren't there, and if they were, he had visuals for it.
Fairport Convention - Short film, but we would use Zhang Yimou and create a sort of "Raise the Red Lantern" to Matty Groves.
Jethro Tull - Passion Play. Ultimately, one of the most exciting prospects, and we would complete it with a dead ballerina to give the fans the excitement it deserves ... AND ... we could even do the whole thing as a ballet ... which would be even more exciting ... though "prog" fans would think it is weird since they do not know what ballet is (hahahahaha!!!!!).
Roger - Amused to Death ... has more visuals in the lyrics that 99% of all rock music pieces, considering many of the songs are about news pieces, from China to many other spots ... this one would be easy to do, too, but I think Roger would not like it ... and we might have to wait for him to pass on!
Incredible String Band ... Would call it "Be Glad That the Song Never Went Away" ... and redo the original film with many of the band's highlights and music. Sadly, most "progressive" and "prog" folks would walkout, because the guitar thrashing is not loud and does not use a Marshall stack!
Robert Wyatt ... Different Every Time. The perfect film. You could just about put anything on it, and he would make it work. We might even make sure that we have 10 kids (pre-teens) all do the shooting so that the ideals of his music and singing, come through loud and clear. It would make this very different, and certainly something that only a few could enjoy though, but then, that's not like some other films and directors are not the same thing.
Tangerine Dream ... Phaedra. Not that it needs it, but this deserves a visual treatment that makes all the others look childish. So many other pieces of theirs fit in this realm it is almost scary. I do think that the Quantum BS folks would not like it!
There is, on one other thread somewhere here, a couple of things that could be done visually with some pieces of music, and I had written a series of stagings for them ... unfortunately I can not find them right now.