Coming to this a little late. I guess I'm of those "blues fans" - sorry kh1958 - but I recommend starting with Buddy Guy's Chess sides (there are some novelty items there, but also some very fine tracks). Then I'd try A Man and His Blues on Vanguard (somewhat low key but very intense) - both of these choices already recommended by others - just thought I'd join the chorus.
Also, check out his recordings for Artistic - pre-Chess. There were only four issued cuts, but there are also alternate takes floating around, if you're into that kind of thing.
As for Gatemouth, as others have said, go with the Peacock sides - available on Rounder and Classics. Dan Gould mentioned his Sings Louis Jordan record. It's one his better later recordings - the best I've heard.