Dave Mustane has always been big on quality recordings, a lot of Megadeth stuff has imaging and layers in the soundstage you just don't hear often with metal. Tool and NIN as well.
Megadeth Dread and the Fugitive Mind is one that I use during voicing of every new speaker design. It's a track that makes imbalance in the 800-1500hz range very easy to discern.
I am also a metal head and love the heavy metal of the 80's and 90's. I love to play NWOBHM bands on my main system. I also like folk metal like the Russian band Arkona and the Hungarian band Dalriada
Oh boy. That's my favourite album with one of my fav guitarist Marty Friedman. The solos on Hanger 18 , Holy Wars ...and Tornado of soul is just amazing. Rock on !!!