For me the biggest ones are...
Mekong delta for the thrash/prog metal, groundbreaking band. Fates warning close second. (More of a power metal w prog influence.
Bathory s/t LP. Bathory spawned 2 genres (I despise the genre thing, as me in the early 80’s it was either metal, or it wasn’t.) this album changed music forever.
Venom -welcome to hell. INFLUENCED BY MOTÖRHEAD, this release influenced about every metal band since. Release date I think was Dec. 1, or 2, or 3, I do remember it was the first week of December. 1981, this slab of unholiness was released and people flipped out, as did I. Still a personal fav, this album changed music forever.
paul Samson, Paul and Paul alone single handily started the amazing NWOBHM scene. Arguably, I’m a huge fan of the British scene, and the dates of Samson’s releases predate much of the so called NWOBHM movement. Lots of singles and bands were also a huge part of this British influence.
Either way, I’m so glad to be a part of the start of metal, the decline, and the rebirth!
long live metal!