I just bought 'The London Howlin' Wolf Sessions' cd, which in addition to Howlin' Wolf's fantastic gritty raw voice, features musicians such as Eric Clapton, Steve Winwood, Bill Wyman, Charlie Watts, even Ringo on drums for one song, and assorted other Brits. The combination is just plain wicked.
What are your favorite blues guitarists or singers? I also enjoy BB King, Magic Slim, et al. The White Stripes and the Jon Spencer Blues Explosion are both great modern groups for the bluesiness. They can be classics, contemporaries, or heavily blues-inspired, it's all good!
(they got the blues)