If I had a spare Benjamin on hand, I'd be tempted to test a HD6670 on Skyrim, but I don't think I'd recommend it for you. Still, you may not need to max your budget.
Jeremy Soule's music is awesome. I went so far as to buy the three Guild Wars sound tracks, and burned them to CDs.
Edit: Taking a look at http://www.videocardbenchmark.net/gpu.php?gpu=Radeon+HD+6670
especially the second chart, a GTX560Ti appears to offer a much higher bang/buck than the HD6950. That's what I'm using, and Skyrim is on all Ultra settings.