The albums below is my definition of extreme metal music, regardless of their genre. Entire list is based only on my personal preferences in metal.
Rules:
1. One album per band
2. 305 groups/305 albums

1.In Flames - Clayman

2.Metallica - ...And Justice For All

3.Chimaira - Chimaira

4.Death - Symbolic

5.Testament - The New Order

      View entire list ››

Must Listen: The First 7

1.Ayreon - 01011001

2.Firewind - The Premonition

3.Amon Amarth - Twilight Of The Thunder God

4.Warrel Dane - Praises To The War Machine

5.Disturbed - Indestructible

      View entire list ››

One album per artist in alphabetical order which happen to be my favorites. Feels like an addendum to the ?Beginner's Guide To Building A Prog Collection" (http://www.metalstorm.net/users/list.php?list_id=58) often mentioning the same band but different releases.

1.36 Crazyfists - A Snow Capped Romance

2.Agrypnie - 16[485]

3.Ahab - The Call Of The Wretched Sea

4.Akercocke - Words That Go Unspoken, Deeds That Go Undone

5.Alkaloid - Liquid Anatomy

      View entire list ››

1.Esoteric - The Maniacal Vale

2.Darkspace - Dark Space III

3.Equilibrium - Sagas

4.Septicflesh - Communion

5.Ayreon - 01011001

      View entire list ››

Each band featured once, except one.

1.Amorphis - Queen Of Time

2.Be'lakor - Of Breath And Bone

3.Burzum - Filosofem

4.Children Of Bodom - Hate Crew Deathroll

5.Dark Tranquillity - Atoma

      View entire list ››

1.Kypck - Черно

2.Septicflesh - Communion

3.Enslaved - Vertebrae

4.Machinae Supremacy - Overworld

5.Draconian - Turning Season Within

      View entire list ››

1.Amon Amarth - Twilight Of The Thunder God

2.Ayreon - 01011001

3.Bloodbath - The Fathomless Mastery

4.Cavalera Conspiracy - Inflikted

5.Cynic - Traced In Air

      View entire list ››

I think this will be a collection of albums I dig. They're in no particular order either

1.Dark Fortress - Ylem

2.Dominia - Judgement of Tormented Souls

3.Be'lakor - Of Breath And Bone

4.Darkthrone - Transilvanian Hunger

5.Darkthrone - Panzerfaust

      View entire list ››

Based my choices on which tracks I enjoy listening to the most

1.Septicflesh - Sumerian Daemons

2.Septicflesh - Communion

3.Septicflesh - Titan

4.Septicflesh - Codex Omega

5.Septicflesh - Sumerian Daemons

      View entire list ››

1.Wintersun - Wintersun

2.Be'lakor - Stone's Reach

3.Ensiferum - Ensiferum

4.Septicflesh - Communion

5.Insomnium - Above The Weeping World

      View entire list ››

For now the albums aren't in no particular order. I was blown away and still love all this albums after years listening. Trying to put 1 per band maximum, maybe more if they have different but awesome eras. Still in progress

1.Opeth - Blackwater Park

2.Angra - Temple Of Shadows

3.Death - Symbolic

4.Blind Guardian - Somewhere Far Beyond

5.Metallica - Ride the Lightning

      View entire list ››

I will be filling the gap years with more albums soon... :3

1.IDLES - Brutalism

2.Radiohead - A Moon Shaped Pool

3.Ghost - Meliora

4.Septicflesh - Titan

5.Twenty One Pilots - Vessel

      View entire list ››

1.Septicflesh - Communion

2.Opeth - Watershed

3.Moonspell - Night Eternal

4.Meshuggah - ObZen

5.Enslaved - Vertebrae

      View entire list ››

1.Agent Steel - Unstoppable Force

2.Annihilator - Alice In Hell

3.Anthrax - Among The Living

4.Artillery - By Inheritance

5.Baphomet - The Dead Shall Inherit

      View entire list ››

1.In Flames - Reroute To Remain

2.Katatonia - Viva Emptiness

3.Crematory - Pray

4.The Project Hate MCMXCIX - Armageddon March Eternal (Symphonies Of Slit Wrists)

5.Mercenary - The Hours That Remain

      View entire list ››