The Eno and Cluster collaborations are pretty cool too. I love all of that kind of stuff.
My dad was a Tangerine Dream fan when I was growing up, so I've always appreciated Phaedra, Rubycon, Stratosfear, and the Sorcerer soundtrack. I recently got hip to Edgar Froese's "Stuntman" solo album. Can't believe I had never heard it before. Love it.