Well done for discovering this guy... he is brilliant !
Copperhead Road is one of his earlier albums and the title track still sends shivers up my spine ! His work with the Dukes is great too, so you can't go wrong there... I love *Shut Up and Die Like An Aviator* - there's some cracking tracks on there.. from Guitar Town to I Ain't Ever Satisfied...
I own all of his albums and would find it hard to jettison any of them.... so my advice is to buy them all (gradually, if you can) and then start buying some of his sister's work - Stacey Earle - she is another amazing musician ....hehe... what have I started now..