I respect Dio a lot more than I do Ozzy, but there was so much classic music during the Ozzy era of Sabbath that I can't vote for anyone else. Ozzy.
01/18 & 01/19 -- Godspeed You! Black Emperor and Neurosis (in Montreal)
02/08 -- Dark Tranquility
04/11 -- Black Sabbath
04/24 -- Nile