When will hollywood learn that there are some things that can't be made into good live-action movies. Sure, sometimes it happens, like Lord of the Rings and, uh, um, let me get back to you on that point. Anyway, the reason is, to get enough sfx money to do something like sci-fi manga/anime right, it has to be a big-budget hollywood production, which means to big stars and big producers to go along with it. Studio's gotta get paid, so they squish the plot and characters around so that it ticks all the "sure hit" boxes on their checklist, and we lose all the subtlety and uniqueness of the stories.
So, based on this reasoning, here is my partial list of things that can't be made into movies (some already mentioned):
Akira
Ghost in the Shell
Cowboy Bebop
Snowcrash
Neuromancer
Sandman
etc.
Oh, and any video game with a good narrative, but the "Extra Credit" guys have covered that territory pretty well.