The Official Ozzy Osbourne Site | The official Ozzy Osbourne site

in terms of what? Each had/has several excellent qualities

uniquness - Ozzy
Power and range - Dio
Range and versatillity - Tony Martin
Range and attitude - Ian Gillan
Ability - Glenn Hughes
Power, range, versatility - Ray Gillen )Best IMO)

Tony Iommi = God, his arch angels are Ozzy Osbourne, Dave Walker, Ronnie James Dio, Ian Gillan, Dave Donato, Glenn Hughes, Ray Gillen, Tony Martin, and Bill Ward (bassically everyone who sang on a song labeled Black Sabbath)