Meh, some good stuff there, a few things I noticed;
Rush - I think Permanent Waves and at least a couple of their later outputs should be present.
Thin Lizzy - Black Rose should be added
Malmsteen - His debut should be here
Judas Priest - Stained Class should be here, as should Jugulator
Iron Maiden - The X Factor should be added
Mercyful Fate - No Melissa??
Children of Bodom - Hate Crew is here, but why not Hatebreeder or Reaper?
No Hammerfall?
Korn - The Path of Totality. I love Korn but what the hell? Just because it contains Dubstep doesn't mean you need to hear it to understand metal.
Lulu and Dedicated To Chaos do not need to be here at all
No Green Carnation?
No Watchtower?
No Halford or Dickinson solo albums?
No Amorphis?
What about more AOR stuff like Harem Scarem, Hardline, Pink Cream 69, Jorn Lande, Talisman etc.
Was there any Symphony X?
No Evergrey?
Not sure if there was any Accept of UDO?
I could go on.
A lot of those punk and alternative albums I never need to hear, they could be replaced with other great metal acts and albums that have been neglected here.