mmm.....thats a tricky question,so my answer will be xtremely minimal.
i always loved that deep,sweet sound that could travel you non-stop.California Sunshine for example.tracks like Forest(!),Secrects Behind The Universe and Utopia(!) from his last album.Or that track from Chi AD,The Flame of Eternal Life(what a trip).But my favorites are Hallucinogen and X-dream.And you cant really decribe them as a specific style right?