Smokestack Lightning or just about anything by Howlin' Wolf. Wang Dang Doodle also by Howlin' Wolf (also duet with Koko Taylor). If you are unfamiliar - study Willie Dixon. The writer of more real blues songs that I have seen on this entire list. P.S. the estate of Willie Dixon sued the crap out of Led Zeppelin for plagiarism of many of his songs. Educate yourself, folks. Most of the people on this list were standing on the shoulders of giants (Etta James, Billie Holiday, Muddy Waters...pretty much the entire Chess catalogue).