I'm not too familiar with Ryan Adams but he does a really cool cover of Wasted Years.

http://consequenceofsound.net/2011/08/check-out-ryan-adams-covers-iron-maidens-wasted-years/

Here is a list of his top 13 metal songs, quite the assortment.

http://www.brooklynvegan.com/archives/2008/12/the_13_metal_so.html

Heard the cover a couple of days ago. I quite liked it, I was surprised at how well the song lends itself to an acoustic arrangement.

Cool of him to openly admit to being a metal fan. So many of his type would completely deny it . His list was pretty good too.

Not just a run of the mill list either. Some really obscure picks too.