As well as a metalhead, I am also a longtime fan of classical and baroque era music, and lately I have been listening to more of the latter. Let's discuss dark-sounding minor key pieces that appeal to the metal heart.

Why not follow your own words and post something worth reading?

i think one of the most obvious examples would be Prokofiev's Dance of the Knights from his Romeo and Juliet op.64. It's got all you could want, that sinister arpeggio on top of the all encompassing and pure evil E->G progression is what I think metal would sound like if it was played with orchestral instrumentation! And im sure everybody has heard Necrophagist's rendition of it at the end of Only Ash Remains, quality stuff.