I like the old school outlaw country singers like Waylon Jennings, David Allen Coe, Merle Haggard, Hank Williams Jr and Johnny Cash. I have to admit to not being a huge fan of Willie Nelson though. As was already stated, much of country music from that era was well recorded and produced. Also, a lot of it is, more or less, unadorned with little processing. Maybe some eq leveling but nothing dramatic.