Second, Kern River. Also, if you like Merle Haggard, give Joe Nichols a try. I think he has the best male voice in country music in recent history, although his choice of material has not always been the best. However, his "Revelation" album is quite good and he is certainly influenced by Merle. Also, if you want to go back to Merle's influences, you can try Lefty Frizell and Vern Gosdin.
