"no metal"
Last 20 years (so anything from 1990 to now) Ok, then without thinking about it too hard, I'd have to say:
Guns N Roses - Use Your Illusion II (1991)
Personally, I don't consider GnR to be "metal" but more or less just hard rock. However, if that is considered to "hard" for the purpose of the thread, then without thinking too hard about it, I'll take this gem:
Prince - Diamonds and Pearls (1991)
Cool picks Lynch
Though I could also go for Illusion I and Prince 'Symbol'