I have to say my favorite so far (and it will be hard to beat) is the Western Highlands field music. (https://www.youtube.com/watch?v=c9xYNN0vs7Y)

Traveling through with the frozen corpses of dragons lying around and other remnants of battle scarring the area to this music is pretty amazing.

It really accurately reflects the feelings of "war, sadness, and death" and "scarred beauty" that I get from the visuals of the place. The music sounds troubled and sad but serene at the same time, like a battlefield after a battle.