I can only listen to ( ) during the cold winter months. It just doesn't feel right to listen to it any other time. Jonsi has a solo project he is touring with now too.
Liquid Drum'nd'Bass.
Great YouTube channels: http://www.youtube.com/user/chill4dnb
http://www.youtube.com/user/liquicity?blend=1&ob=4
http://www.youtube.com/user/dubplatenews
Enjoy.
Don't judge the book by it's cover and atleast give it a try
Darkwave
http://www.youtube.com/watch?v=0ad7s6wHWIg
And this band I found recently called Apostisy is really relaxing to me for some reason... melodic blackened Death metal.
http://www.youtube.com/watch?v=e-9bZuXqNq0
John Mayer's latest album (name escapes me). Assassin, Crossraods, Half of my Heart. Some really soothing music there.
I'm with Marakh, Sigur Ros is defietly up there, but for me its My Morning Jacket.
I usually listen to progressive rock, like Porcupine Tree, Amplifier, Cire, Demians and occasionally a few trance songs which I like at the time.(though I usually find it hard to find good trance which i enjoy XD)