I am a huge fan of Johnny Cash. My favourites of his early stuff are "Come In Stranger" b/w "(I Don't Like It But I) Guess Things Happen That Way". I prefer his Sun recordings to much of what he did at Columbia. He did do an album Called Ride This Train, which was wonderful, it was on Columbia. I don't think it has ever been released as a CD.
He did some grand things late in his career, best cover of Leonard Cohen's Bird on a Wire. A real American legend.