The first movie that so should be made, but will never be is a simple one-
Ghost In The Shell by Michael Mann.
Why? Because...when I first saw Heat, I realized that this film could so easily be adapted to the vision of a post-cyberpunk world that I saw Mamoru Oshii pull off in his production. Mann is an artist with color...all the scenes that are of a character in the film are shot in a particular color type (the character of Neil McCauley, played beautifully by Robert DeNiro, tends to be stark, simple, and blue while Vincent Hanna-played superbly by Al Pachino-is colorful and complicated. We never see Vincent in anything other than complexity, all the angles filled). All the shots are stylized-night is the "normal," all the daylight shots are flat and bleached out.
Ignore the gunfights-which are beautiful, by the way. Ignore the crime drama. Ignore everything else...at the heart of it is two stories of two lonely, alienated men-Neil due to the discipline he maintains ("Don't let yourself get attached to anything you are not willing to walk out on in 30 seconds flat if you feel the heat around the corner") and Vincent whom is working on pretty much failed marriage #3 and personal relationships that he's willing to toss aside for anything that gets in the way of catching guys like Neil. Two guys that admit that they respect each and like each other, but one day will probably have to kill the other because that's the discipline they're both under.
Ghost In The Shell is about alienation as well. For Major Kusanagi, does she really exist? Is there a brain in her skull, a ghost in her soul? Or is she just all software that mimics human existence? There's an iconic scene in the movie where Kusanagi is on a boat, and she sees a woman that might as well be her twin sister-or somebody using the same cybernetic body (the video is here on YouTube, 0:39 to 0:52). There's the last chase, as Section 9 hunts down the team that stole the Puppetmaster body from them for Section 6, using this iconic music as a part of the chase scene.
I can damn well see, in my mind, the film-shot for shot-with Michael Mann directing it. I can see the Major and Batou in their boat, talking about their circumstances. Or the chase scene through the market...not a shot for shot adaptation but one where Batou grabs items to make himself seem a bit more like the crowd as he hunts for an invisible man. And, the final, climatic gun fight...man vs. machine vs. man.
Of course, a US version is being made by Steven Speilberg, but I think that he'll miss the point, which is awful. Still, one can dream.
UPDATE: A great blog posting on the real life locations that inspired the movie. Worth looking at, and the rest of the blog, too.