Ultimate Timeline of METAL MUSIC Milestone Moments

World Downfall - Terrorizer. Basically invented deathgrind

Left Hand Path - Entombed. The first big album from the Swedish death metal scene.

Beneath The Remains - Sepultura. I know you have them under 1986, but this was a huge milestone album.

1994:

Burn My Eyes - Machine Head.

Others:

Cannibal Corpse probably needs a mention. I'd go for Butchered at Birth rather than Eaten Back to Life.

Carcass needs a mention. They invented goregrind with the first two albums, Necroticism was voted Terrorizer magazine's album of the decade for the 1990s (it was highly influential), and Heartwork blah blah... melodic crap.

Slipknot?

That's just from a quick look, but that's a good fun, cool sort of list!

Vim Fuego wrote: 1989: World Downfall - Terrorizer. Basically invented deathgrind Left Hand Path - Entombed. The first big album from the Swedish death metal scene. Beneath The Remains - Sepultura. I know you have them under 1986, but this was a huge milestone album. 1994: Burn My Eyes - Machine Head. Others: Cannibal Corpse probably needs a mention. I'd go for Butchered at Birth rather than Eaten Back to Life. Carcass needs a mention. They invented goregrind with the first two albums, Necroticism was voted Terrorizer magazine's album of the decade for the 1990s (it was highly influential), and Heartwork blah blah... melodic crap. Slipknot? That's just from a quick look, but that's a good fun, cool sort of list!

^ @ Adam, thanks for the suggestions! I considered Blind Guardian but Helloween beat them to the power metal thing. I can't include everyone only firsts and interesting unique examples. I own all Blind Guardian albums so i'm familiar with each album. Epica sounds like an interesting case.

I'll check into Cruachan (which i'm not so familiar with) and the last two you suggested, Adam. I'm sure there are many oddballs out there i've never encountered. I just thought of quite a few yesterday that i added myself!

I'll have to chew on all this later.

@Vim. I dunna, Cannibal Corpse may be the most popular death metal band but they don't have a single album that was unique really. They weren't the first death metal band and even the parental advisory first goes to 2 Live Crew not a metal band. Sepultura might be a good consideration. Burn Your Eyes wasn't even close to the first groove metal. Pantera wins that distinction hands down. I own most Machine Head albums and i don't find them innovative or unique but thankis for the suggestions!

Do keep em coming :)

The first two albums are obviously more speed metal. Tales From the Twilight World is their first power metal album but it still has speed metal elements. On Somewhere Far Beyond they refined this sound. However either would be an acceptable inclusion. As an aside they are also a good example of a metal act who knows how to do soft ballads right. 

You've also got to remember that Helloween's Keeper of the Seven Keys albums actually have a very old school sound very like trad heavy metal. They don't fully represent the refined genre of power metal any more than early Black Sabbath represents fully refined heavy metal. Helloween also drifted from what they'd created heavily through the remainder of Kiske's era. Some may call Pink Bubbles Go Ape power metal, but it's really only got a scant few elements and Chameleon is pretty laughable to even consider a metal album. It was only when Deris took over that they returned to power metal and produced anything that might be considered in the same harder power metal league as what Blind Guardian were doing. By that time Blind Guardian had released both Tales and Somewhere and further refined the genre as a whole along with its harder German sound. Of course in terms of refining a sound, you can't discount Gamma Ray either, although I don't personally consider them landmark until Kai Hansen became the lead vocalist for Land of the Free.