Definitely more towards the progressive side of things. And the heavier stuff, for the most part.
My favourite band would be Meshuggah. Brutal, complex, precise metal that just wipes the floor with anything else out there. Also a big fan of Dead Can Dance, Pink Floyd, Coroner, Massive Attack, Devin Townsend's projects (Strapping Young Lad, Ocean Machine, Infinity), Frank Zappa, King Crimson, YES, Genesis (mostly before Phil Collins took the lead), Opeth, Ozric Tentacles, Soundgarden, Mike Oldfield, Something For Kate, Underworld, Aphex Twin, Squarepusher, Mark Hollis, Bjork, Oceansize, NIN (mostly The Fragile and earlier) and Grand Silent System (an awesome Australian band).