Ryan Adams is one of those annoying songwriters who would rather be prolific than good. His songs can be good, great even, but until he stops releasing two albums a year most of them will never make an impact. I'll recommend The Best of Ryan Adams in advance.
Despite his inability to tell his own good songs from his bad songs, Adams has enough of an ear to hear Iron Maiden's "Wasted Years" as a folk ballad and Alice in Chains' "Down in a Hole" as alt-country.
His live covers of Danzig's "Mother" and Dio's "Holy Diver" also deserve listens. I'd risk a Hamilton for a Ryan Adams acoustic metal album.