I could be typing this out until tomorrow there's so many...
but I'll stick with my trump cards here:
Frank Sinatra
Muddy Waters
Each have a TON of songs that are impactful, so pick your choice.
EDIT: One more. If you're looking for a CD full of sad, slow, beautiful tunes, get the Trinity Session by the Cowboy Junkies.
It's a killer. Margo Timmins has one of the most alluring female voices around, IMHO.
Sade is another...
Into classical music? If you're into some REALLY deep instrumental stuff, try one of the traditional standbys:
Richard Wagner
There's a fair amount of gypsy and flamenco guitar that's rather spirited and moving as well, on both ends of the spectrum.
