TLU is one of my all-time favorites. I first saw it when I was 7 or 8, but of course back then I couldn't see just how somber the story is, I just liked the (pseudo-)anime look and the music. Later on, on subsequent viewings, I began to see the intricate details of the plot and character complexities and developed a deep fascination with the film and its history. I like to see it as the first in my "Angela Lansbury Trilogy"
-- the lady has voiced characters in my top three animated films (TLU, BaTB, Anastasia
I have yet to read the novel but it's on my list. I know a lot about it, though, so I doubt a live-action adaptation would do it any more justice than the 1982 film. If anything, it would be dumbed down to meet the Hollywood requirements and audiences' penchant for overblown CG crapfests. If there ever was a perfect time for dark fantasy films it was the '80s, and TLU hit it just right.