My current top 10, in no particular order;
Really, I guess it is just a coincidence that the most mind-bendingly awesome one tops the list...
King Crimson-Starless and Bible Black
I could endlessly listen to proto-metal circa 68-72
Iron Butterfly - Heavy
Deep Purple - Deep Purple (did they wait until their third album to self title just to be different or because this album is so good they wanted their name on it twice?)
King Crimson - In the Court of the Crimson King
Uriah Heep - Demons and Wizards
But I also like just about everything else except what passes for country music the last decade or so.