I'm one of those odd blends of things, though most of what I listen to tends to have high-quality musicianship attached, unless it's unique and sonically pleasing enough to catch my interest. For example, Pink Floyd has been my favorite band for more than ten years now. Under that, in no order at all, you have:
Vivaldi
Behemoth
Black Sabbath
Orff
Children of Bodom
Dethklok
Shostakovich
ELP
Genesis
Mahler
Stravinsky (now playing)
Immortal
Iron Maiden
Sibelius
Jethro Tull
Jimi Hendrix
Bach
King Crimson
Korn
Led Zeppelin
Mayhem's first album due to Attila Csihar
Megadeth
Metallica
Mushroomhead
Nirvana
Outworld
Glass
(Richard) Strauss
Rush
Serj Tankian
Slayer
Slipknot
Sunn O)))
System of a Down
The Who
Wolfe Tones