first off, it's only right for me to suggest calm radio.. that is a really good service- and has helped me out a lot

on that site you can listen to various stations.. so just piano music, just violin music, movie soundtracks, the works- they even have atmosphere channels.. so channels dedicated to playing ocean sounds- and other nature things

go to:

www.calmradio.com

as for individual artists / albums i'd suggest the following:

100 of the world's best melodies (compilation album)

blue sky classics- dan gibbson

anything by john seri

anything from hilary stag (love her music)

enya

kioti oldman

the album destiny by jim brickman (mainly piano)

anything by liquid mind

if you like pan pipe music, then ken davis

meditation music volume 5 (great compilation)

patrick ball

the mystic moods orkestra

and then, you can go for the original composers.. vivaldi, handle, mozart, etc.

hope this helps