Inspired by Linden's recent post, I'm going to list the bands I like. This won't be a complete list, as there are several bands I only have one album of (so far), but this will cover those I consider my favorites.

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A.C.T
A Perfect Circle
Age of Nemesis
Allen/Lande
Andromeda
Animations
Anubis Gate
Arena
Ayreon
Balance of Power
Beardfish
Black Bonzo
Blackfield
Cloudscape
Coheed & Cambria
Dark Tranquillity
Dream Theater
Enchant
Everon
Iced Earth
In Flames
Kamelot
Magnitude 9
Meat Loaf
Mind's Eye
Nightwish
No-Man
Odd Logic
Opeth
OSI
Pagan's Mind
Pain of Salvation
Phideaux
Pink Cream 69
Porcupine Tree
Queensryche
Riverside
Rush
Satellite
Section A
Serenity
Soilwork
Spock's Beard
Starbreaker
Sylvan
Symphony X
Therion
Threshold
Tool
Vanden Plas
Vision Divine
Within Temptation
Yes