There are probably some I left out.
Subject to change.

Have at least 1 full-length album of each band.

Also this is more for personal use/reference.

...and Oceans
:wumpscut:
1349
3 Inches of Blood
Abigail Williams
Aborted
Aborym
The Absence
Ad Hominem
Aeon
Agalloch
Agathodaimon
Alcest
Alkonost
Amon Amarth
Anaal Nathrakh
Anata
Annihilator
Anorexia Nervosa
Arch Enemy
Arcturus
Arsis
Atrium Carceri
At The Gates
Augury
Axenstar
Ayreon
Balrog
Bathory
Behemoth
Belphegor
Beneath The Massacre
Benighted
Black Sabbath
Blacklodge
Blind Guardian
Blood Duster
Blood Red Throne
Bloodbath
Blotted Science
Bolt Thrower
Borknagar
Burzum
Callenish Circle
Candlemass
Cannibal Corpse
Capricornus
Carcass
Carpathian Forest
Celtic Frost
Children Of Bodom
Circle Of Dead Children
Clint Mansell
The CNK
Comatose Vigil
Cryptopsy
DÅÅTH
Dargaard
Dark Funeral
Dark Tranquillity
Darkane
Darkspace
Darkthrone
Daylight Dies
Death
Death Angel
Deathspell Omega
Decapitated
Decrepit Birth
Defeated Sanity
Deicide
Demiurg
Demons & Wizards
Deströyer 666
Destruction
Dethklok
Devin Townsend (Band)
Dew-Scented
Diabolical Masquerade
Dimmu Borgir
Disiplin
Dissection
DOOM:VS
Draconian
Dragonlord
Drastus
Dream Theater
Drudkh
Edge of Sanity
Edguy
Elend
Emeth
Emperor
Ensiferum
Enslaved
Enthroned
Entombed
Exhumed
Exodus
Falkenbach
Flame
Forest Of Impaled
Forgotten Tomb
Funeral Mist
Gehenna
Goatwhore
God Dethroned
Gojira
Gorgoroth
Gorod
Graveworm
Green Carnation
Grendel
Hammerfall
High On Fire
Hour of Penance
Hypocrisy
Ice Ages
Iconoclasm
Immolation
Immortal
Impaled Nazarene
In Flames
Insomnium
In The Woods...
Into Eternity
Insision
Iron Maiden
Judas Priest
Kalmah
Kataklysm
Katatonia
Kataxu
Khors
Kreator
Kriegsmaschine
Krisiun
Kromlek
Kronos
Lair of the Minotaur
Lamb Of God
Ljå
Lord Belial
Lost Legacy
Luca Turilli
Lurker Of Chalice
Lustmord
Lutomsyl
Machine Head
Malevolent Creation
Manowar
Marduk
Martyr
Mastodon
Mayhem
Megadeth
Melechesh
Meshuggah
Metallica
Mirrorthrone
Morbid Angel
Mors Principium Est
Myrkr
Myrkskog
Naglfar
Napalm Death
Necrophagist
Necrophobic
Negura Bunget
Neuraxis
Nevermore
Nightrage
Nightwish
Nile
Nunslaughter
Obituary
Ofermod
Old Man's Child
Old Wainds
Om
Opeth
Origin
Otargos
Overkill
Pain of Salvation
Pandemonium
Pantera
Paradise Lost
The Project Hate MCMXCIX
Professor Fate
Prostitute Disfigurement
Psycroptic
Quo Vadis
Ragnarok
Red Harvest
Rhapsody (of Fire)
Rotting Christ
Samael
Satanic Warmaster
Saturnus
Satyricon
Scar Symmetry
Sear Bliss
Sepultura
Septic Flesh
Seth
Shape Of Despair
The Shadow Order
Sinful
Skepticism
Skinless
Skyfire
Slayer
Sleep Terror
Sodom
Solefald
Sonata Arctica
Soulfly
Strapping Young Lad
Stratovarius
Suffocation
Summoning
Sunn O)))
Swallow The Sun
Symphony X
Taake
Temnozor
Testament
Thine Eyes Bleed
Throes Of Dawn
Thronar
Trans-Siberian Orchestra
Tsjuder
Turisas
Týr
Ulver
Unexpect
Unleashed
V:28
Vader
Varathron
Venom
Vinterriket
Virgin Black
Visceral Bleeding
Windir
Wintersun
Yearning
Yngwie Malmsteen
Zyklon
Zyklon-B