Oak
Oakhelm
Oath Div. 666
Oath Of Damnation
Oathean
Obelyskkh
Obituary
Objector
Obligatorisk Tortyr
Obliteration-NO
Obliteration-UK
Obliveon
Oblivion
Oblivion Protocol
Obscene
Obscene Eulogy
Obscenity
Obscura
Obscura Amentia
Obscura Qalma
Obscurity-GE
Obscurity-SW
Obsecration
Obsequiae
Obsession
Obsidian
Obsidian Shrine
Obsidious
Obsolete Incarnation
Obtained Enslavement
Obtest
Obtruncation
Obus
Obzidian
Occulsed
Occult
Ocean
Oceana
Oceans Of Sadness
Octagon
Octaviagrace
Octinomos
October 31
October Tide
Octopus
Ocultan
Oddland
Oddmongers
Ode In Black
Odhinn
Odin
O.D.I.O
Odious Devotion
Odium-CA
Odium-GE
Odium-NO
Odyssea
Odyssey
Ofermod
Offending
Officium Triste
Of Fire
Of Graves And Gods
Of Hatred Spawn
Of Human Bondage
Of Rytes
Of Spire & Throne
Ofstingan
Of Wrath And Ruin
Ogotay
Okrütnik
Oksennus
Olamot
O.L.D
Old Forest
Old Funeral
Old Man’s Cellar
Old Man’s Child
Old Pagan
Olethrio Rigma
Olio Tähtien Takana
Oliver/Dawson Saxon
Oliver Magnum
Oliviera
Olkoth
Olympos Mons
Omega
Omega Crom
Omega Diatribe
Omega Infinity
Omen
Ominous
Ominous Crucifix
Ominous Ruin
Ominous Scriptures
Ommnus
Omnihility
Omnikage
Omnitron
Omnium Gatherum
Omnipotence
Omophagia
Onchocerciasis Esophagogastroduodenoscopy
Ondfødt
One Day In Fukushima
One Day In Pain
One Man Army And The Undead Quartet
One Master
One Step Beyond
122-Stabwounds
Oneiric Celephaïs
Onirica
Onirophagus
Onkel Tom
Onslaught
On Thorns I Lay
Onward
Oomph!
Opera Diabolicus
Opera IX
Opeth
Ophidian Forest
Ophidian I
Ophis
Ophthalamia
Opposing Motion
Oppressor
Opprobrium
Oracle
Oracles
Orange Goblin
Oranssi Pazuzu
Orationem
Orator
Oratory
Orbit Culture
Orbweaver
Orcrypt
Orcustus
Orden Ogan
Order From Chaos
Order Of Ennead
Order Of Nine
Order Of The Ebon Hand
Order Of The Nameless Ones
Ordinul Negru
Ordo Obsidium
Organ Dealer
Organectomy
Organic Infest
Organ Trail
Orgrel
Origin
Original Sin
Origin Hell
Orm
Örmagna
Ornamentos Del Miedo
Orobas
Orphan
Orphanage
Orphaned Land
Orphique
Orth
Orthodox
Osculum Infame
Oshiego
OSI
Osiris
Osiva
Ósserp
Ossian
Ossuary
Ossuary Anex
Ossuary Insane
Ostrogoth
Osyron
Otargos
Otus
Oubliette
Ouija
Ouroboros-CA
Ouroboros-FR
Outcast-FR
Outcast-GE
Outcasts
Outlaw Order
Outline
Outloud
Outrage
Outremer
Outre-Tombe
Overcast
Overdose-BR
Overdose-GE
Overdose-GE
Overdrive
Overdrive Sensation
Overflash
Overhung
Overkill
Overlife
Overload
Overlord
Overlorde
Overloud
Over Nemesis
Overstep
Overthrow
Overtures
Ovid’s Withering
Oxalate
Oxidize
Oxiplegatz
Oxygen Destroyer
Oz
Ozz
Ozzy Osbourne