Metal has some ridiculous sub-genre, like countless, and then the countless combinations of them. The only other genre of music I can think of that has as many subs is probably electronic which is literally boundless anymore, with only slight deviations in the style making it something completely different. And "Indie" being whatever the fuck it wants to be. The point I'm trying to get is I feel like they're some of the best forms of music because they are so fucking versatile. Metal is even considerably classical music with distortion and screaming, which makes it seem even more "metal". Hell they even come together fairly well in my opinion, most of my favorite black metal bands have post-rock and indie elements.
For some reason though, I haven't seen any like "western" metal. The closest being southern metal which is more about kicking ass, being badass, drinking beer, smoking pot, and punching the devil.
I'm talkin' there ain't no like driving galloping metal with mexican guitar and horns and lyricism about outlaws being pursued into the sunset or train robberies. There are some great covers I've found, but not entire albums about it that I have found yet (if any is known, shit bro link that).
TL;DR I fucking love metal.