townes van zandt is one of my most favorite artists of all time. the best sad country cowboy tunes ever. you may have heard his cover of the rolling stone's "dead flowers" in the big lebowski, which I think is even better than the already amazing original song. Also good, but more like outlaw western is Spindrift.
To everyone who mentioned Hank Williams, Jr. and III, they are also great. Waylon Jennings is fucking awesome as well.