Here's a few of my 10/10 albums.
Kekal - 1000 Thoughts of Violence: avant-garde black metal. As time went on the band strayed further away from black metal but here you've got some really fun dissonant riffing and some really beautiful and epic melodic parts. It's really good.
Queensryche - Operation: Mindcrime: progressive/power metal. It's just extremely tightly written, suspenseful, and atmospheric in all the right ways. The story's also really interesting.
Death - Symbolic: progressive death metal. Not a single bad song on there; Chuck Schuldiner's riffing style is clear as day awesome. A true virtuoso aped but never superseded by many. His life was short, but his influence is everlasting. The candle that burns twice as bright, as they say.