Lets see, this is almost as hard as actually deciding what music to listen to while tripping.
Theres Tool for an amazing spiritual experience, SWpongle (who doesn't?) Kyuss, Bjork, Radiohead if I'm in the mood although it's really more rolling music for me, the latest potishead release is pretty good for tripping, King Crimson, Led Zepplin, Massive Attack, aphex Twin, Meshuggah if my senses can take the pounding, Nine Inch Nails - Ghost I-IV (NIN with singing just doesn't work for me while tripping).