I go to bed everynight that way if I can, to the point where I just sit there and sleep while being awake sorta... its amazing! Even more so with my 5.1 in my room playing my sleep mix for everyone to hear :-D.

There are certain songs that just fuck with my head.
Orbital- Halcyon + On + On... 9 min song of bliss.
Imogen Heap -Hide and Seek and Speeding Cars
The Mars Volta -Vicarious Atonement and Asilos Magdalena both off of Amputechture.
Lastly Elanor Rigby the Beatles, there is a thrice cover out there which does a pretty good job actaully as well.