Game of Thrones now has three soundtracks released, all by Ramin Djawadi (of Iron Man fame). If you've not checked them out, you should probably add that near the top of your bucket list or something. The newest score (Season 3's) might arguably be the best of the bunch, if only because he does some really epic stuff with the character themes. And that's what sets GoT's music apart from many soundtracks out there -- Djawadi is apparently quite the fan of the art of character motifs (as can be heard in this excellent compilation of the first two seasons here). And he knows how to use them, since one theme might have several variations (epic, somber, etc) or combine with other themes to fit the plot. Also he nailed the main theme.