Pretty new to metal - I started listening to it in October 2018, and I don't do it 24/7. Don't expect me yet to be an expert or to know a lot of underground bands. Favorites in certain subgenres so far:
folk metal - Moonsorrow
melodic death metal - Children of Bodom, Be'lakor, Eternal Tears of Sorrow
old school death metal - Entombed, Dismember
progressive metal - Haken, Edge of Sanity, Threshold, Cynic
speed metal - Flotsam and Jetsam
technical thrash metal - Coroner, Watchtower, Toxik, Voivod
teutonic thrash metal - Destruction, Deathrow, Assassin
thrash metal - Megadeth, Death Angel, Xentrix, Whiplash, Metal Church
traditional heavy metal - Iron Maiden, Slauter Xstroyes