This is very true. It is very unique to its sound and how it was put together.

There are some greats listed here (Ween, Jarre, FSOL, Lovage, Aphex, Shpongle, Air, etc.)

However my pick is Mike Oldfield - Ommadawn The only thing similar to this is his own album Incantations a few years later, but there just isnt anything like it from start to finish.