Metallica - Reload
Metallica - ...And Justice for All
First two metal albums I heard. I really had no idea about all the sorts of music out there and some classmates just told me about Metallica specifically. I'd heard a few songs from Soundgarden but I hated them at first. Reload established that I was gonna like that stuff at the mild end of the metal scale after all - Alice in Chains, Danzig and so on. Meanwhile, Justice was the gateway to everything heavier.
I could name punk album
Big Blue Blanket - Everytime You Smile as a gateway too. It's the first album I liked where only half of the lyrics are decipherable due to the singing style. It was a band local to my uncle. He gifted the CD to my sister and I disliked it at first. I guess I had to hear Metallica first, and then I was surprised to come back to Big Blue Blanket and like them. It's not your ordinary punk. It's ska-influenced in places but often downbeat with longish brooding songs in the 4½-6½ minute range (the last track is 10 minutes but the majority of that is a couple of hidden songs that segue together).
Metallica - Garage Inc. - Still on my beginnings starting with Metallica and can't go past this either. All the bands they covered were new to me apart from Queen and Lynyrd Skynyrd. So this was my introduction to Diamond Head, Budgie, Motörhead, Black Sabbath, Mercyful Fate, NWOBHM in general and more. Even the bands only mentioned in the liner notes such as Bow Wow and Paralex became something for me to seek out.
Then the mp3 explosion happened... but aside from still buying CDs, I wasn't usually checking out full albums due to dial-up speed and limited hard drive space. So it's hard to know what to name next. There'll be albums I name where I only heard part of them at first and then the full thing years later.
Black Sabbath - Black Sabbath - Gateway to doom, checking out Candlemass, Electric Wizard etc. and later the local stoner/doom scene.
Sticky Filth - Archives - A compilation from a punk band, but some really metallic songs such as
Witch Hazel, spun this heaps. One of my gateways to bands crossing over the punk/metal divide - Plasmatics, English Dogs, The Accüsed etc.
Mercyful Fate - Melissa - A gateway to more extreme things.
Girlschool - Hit and Run - Favourite album from the NWOBHM which became a big deal for me so I'll give this a mention. They didn't get me into female-fronted bands as much as The Runaways/Joan Jett, but still a factor.
Black Boned Angel - Supereclipse - Drone metal, my gateway to bands with hour-long doom or experimental songs, and probably instrumental post-metal somewhat too. Heard the altered reissue first like most people would've.
It's hard to cover everything. Guess I'll throw some death metal in and go with
Ulcerate - Everything Is Fire. Not that I hadn't been entertained by death metal albums before, but it was a turning point where one that I seriously gave a fuck about came along and I got more interested in the subgenre. I'd enjoyed Grave and Morbid Angel live somewhat, but only knew one album from each of them and hadn't been inclined to check out more.