Not sure really, my tastes in music have changed quite a bit over the past couple of years. I still listen to most of artists I did awhile ago, but now I'm more into various genres of metal than anything. But a few I know I will never get tired of are:
Pink Floyd: The Division Bell, Wish You Were Here, Dark Side of the Moon
Opeth: Damnation, Blackwater Park
Clint Mansell: The Fountain OST
Dark Tranquillity: Fiction
Dir en grey: Withering to death.
Mudvayne: The End of All Things to Come
Trivium: Ascendancy, Ember to Enferno