Metal came slowly to me.
I listened to a little Kiss when I was a teenager, mostly because one of my best friends was heavily into Kiss so we'd put it on at his place. But Queen was my favorite band then (and still is).
Then at University in the early 90s I disovered Metallica, of whom I love the "Black album" the most, but enjoy their earlier 'speed' phase too.
I caught onto Manowar while in the Army.
THen it took a while before I ventured future into Metal with Iron Maiden (again due to friends), and from there I've sunk into it
I used to visit the record store, look for covers that looked interesting and listened to them. How I caught onto Rhapsody and Blind Guardian.
Nighwish fast became a great favorite. I love their first vocalist, and their third. The second was forgettable.
Some of my favorite bands now are:
Iron Maiden - I love their journey into more Progressive Metal
Candlemass - Epic Doom Metal.
Opeth - the masters of Progressive Metal
Some of these bands are the only ones I've explored in their genres.
I dislike a growling vocal, but a couple of bands have done it in ways that I can enjoy it, but mixing clear and growl. Black Metal I've never gotten into, nor see a desire to explore. Their growling turns me off.
Goth Metal (Nighwish, Epica, ++) with a clear female vocal and growling male has long been a favorite genre.