I'm on a King Diamond/Mercyful Fate binge, having ordered the new live blu-ray last week and waiting for it's release in another 2 weeks. I had ignored 90's Mercyful Fate, since I'd always believed Melissa and Don't Break the Oath were held as their best records. I love some of these 90's albums with the heavier guitars. Certainly better than some of King's 90's output.
King Diamond - The Puppet Master
King Diamond - Conspiracy
Mercyful Fate - Dead Again
Them - House of the Se7en Gables (King Diamond worship gallore from this band)
Witherfall - A Prelude to Sorrow
Lost Domain as well.