This is a good thread--a lot of good suggestions. I approve.
I don't know if anyone else here is fond of the Chicago Blues, but if we're sharing,
Luther Allison is a fabulous and rather undeservedly obscure Bluesman. He wasn't ever a really groundbreaking artist, but he combines spectacular arrangements with incredibly soulful vocals that give a whole new life to a slew of standards. He also did some cool stuff in the 80's and 90's, when for the most part the Chicago Blues was "dead". Worth checking out.