in alphabetical order, soas not to choose favourites, and this is likely to change, and I'm sure I forgot someone, &c. &c.:

Blue Oyster Cult
Crack the Sky
Deep Purple
Golden Earring
Judas Priest
Led Zeppelin
New Model Army
Rush
Scorpions
The Who

The Who is easily last and would be the first to go if I could think of anyone else; Rush is easily first, as they are in my top 10 favourite artists of all time. I'm not sure Priest et al count as "hard rock" and not "heavy metal", but unless I can think of anyone better, they stay. Sabbath are definitely heavy metal, and so they are not on this list. I would also like to point out the complete lack of Bon Jovi and Extreme from my list. Thank you.