I actually got around to organizing a list of music I like. There are some bands that only have a couple of songs that I know and like, so I left them out. These include the Who, David Bowie, the Beatles, Metallica, and more. I only have one classical artist right now, but I may add more in the future after I've listened to more. I'm especially interested in Bach, Paganini, and Mussorgsky, but there are others.

the music I like:

:Wumpscut:
Aarni
Adrian Belew
Agalloch
Agatus
Agent Steel
Age of Nemesis
Ahab
the Alan Parsons Project
Alarum
Alcest
Alkonost
Angra
Angst Skvadron
Annihilator (first 2 albums)
Anthrax (early)
Antonio Lucio Vivaldi
Anubi
Apokatastasia
Arcturus
Art Metal
Atheist
Atomic Rooster
Azure Emote
Banco del Mutuo Soccorso
Bathory
Battles
Beggar's Opera
Belenos
Behold...the Arctopus
Bill Bruford
Bill Bruford's Earthworks
Black Sabbath (Ozzy era and Dio era)
Blind Guardian
Blotted Science
Blut Aus Nord
Boards of Canada
Bongzilla
Boris
Borknagar
Bucovina
Cabaret Voltaire
Camel
Candlemass
Canvas Solaris
Celtic Frost
Coil
Cronian
Cruachan
Cynic
Dan Swanö
Darkestrah
Dark Moor
Dark Suns
Death
Deep Purple
Demilich
Derek Sherinian
Diabolical Masquerade
Dimension F3h
Dio
Disincarnate
Do Make Say Think
Don Caballero
Direwolf
Doomsword
Doom:VS
dot(.)
Dream Theater
Dysrhythmia
Earl Shilton (Alex Thomas)
Earth
Edge of Sanity
Einherjer
Einstürzende Neubauten
Electric Wizard
Elffor
the Elysian Fields
Emerson, Lake and Palmer
Empyrium
Equimanthorn
Esoteric
Exodus (early work)
Falconer
Falkenbach
Fantômas
Fates Warning
Finntroll
Fleurety
the Flower Kings
Focus
Forest of Fog
Frank Zappa and the Mothers of Invention
Gentle Giant
Godflesh
Godspeed You! Black Emperor
Gong
Gonin-Ish
Gordian Knot
le Grand Guignol (formerly known as Vindsval)
Grand Magus
Grave Digger
Hangedup
Hordak
Heidevolk
Helloween
High on Fire
Hrsta
Ice Ages
Ihsahn
Illogicist
Iron Maiden
Isis
Jens Johansson
the Johansson Brothers
the Jimi Hendrix Experience
Jesu
Joe Satriani
John Petrucci
Jordan Rudess
Judas Priest
Kailash
Karaboudjan
Kayo Dot
Kekal
Ken Ishii
King Crimson
King Diamond
King's X
Klabautamann
Korpiklaani
Kromlek
Kyuss
Led Zeppelin
in Lingua Mortua
Liquid Tension Experiment
Liquid Trio Experiment
the Lord Weird Slough Feg
Lux Occulta
Mael Mórdha
Mammatus
Manes
Manowar
Marty Friedman
Mattias IA Eklundh
Maudlin of the Well
Megadeth
Mekong Delta
Melechesh
the Melvins
Mercyful Fate
Minas Tirith
Minsk
Mirrorthrone
Mogwai
Monolithe
Mr. Bungle
Myrkgrav
Necromantia
Necrophagist
Neglected Fields
Negura Bunget
Nektar
Noriyuki Asakura
Nothing
Obscura
Om
Odroerir
Opeth
Orange Goblin
Otyg
Overkill (early work)
Pagan's Mind
Pain of Salvation
Pantera (only Power Metal and Cowboys From Hell)
Pantheist
Peccatum
Pelican
Pentagram
Phlebotomized
Pink Floyd
the Police
Planet X
Platypus
Premiata Forneria Marconi
Primordial
Professor Fate
Proscriptor
Psychotic Waltz
Queen
Queensrÿche
Radiohead
Ramesses
Raventhrone
Realm
Rei Harakami
Reverend Bizarre
Rivendell
Ron Jarzombek
Rosetta
Running Wild
Rush
Rwake
Saint Vitus
the Samuel Jackson Five
Scald
Scale the Summit
Sculptured
Secrets of the Moon
Shadow Gallery
sHEAVY
Sigh
a Silver Mount Zion
Skepticism
Sleep
Smile Carved Sour
Snowblood
Sodom
Solefald
Solitude Aeturnus
Spaced Out
Spastic Ink
Spiral Architect
Spock's Beard
Stratovarius
Steve Hackett
Steve Vai
Summoning
Symphony X
the Tangent
Tangerine Dream
Tankard
Thee Maldoror Kollective (late work)
Thou Art Lord
Thronar
Tomorrow's Eve
Tony Levin
Tool
Toxik
Transatlantic
Transcending Bizarre?
Triumvirat
Trouble
Tumulus
Turisas
Týr
Ufomammut
Ulver
Umbra Nihil
Unexpect
Unorthodox
Uriah Heep
Vanden Plas
Van der Graaf Generator
Ved Buens Ende
Vintersorg
Virus
Void of Silence
Vulture Industries
Watchtower
Waylander
the Wicked
Winds
Witchery
Wormphlegm
Yearning
Yes
YOB
Zandelle
Zebulon Pike
Zemial
Zero Hour
Zoroaster

edit:

Whenever I discover more bands that I like, I'll add them here.

The band, Negura Bunget has a Romanian letter in its name, but NG freaks out when I try to use it, so I just replaced it with an "a".

Here's what happens when I try to use the letter...

%u0103

edit:
There just might be a band or two missing from this list. I was looking over it and realized that Electric Wizard and Winds were not there before. I don't know how that happened, but this could mean that there are others not there that should be there.