Best Blues on CD/SACD?

Try Melvin Taylor and the Slack Band. Anything of his.

michael bloomfield-its not killing me (sony import)

Lets see, where do I begin.
1) On the AVI label Slim Harpo- Hip Shakin, Lightin Slim-
I'm evil, and all other AVI releases of Excello material.
2) Louisinana Blues on Arhoolie, Various Artists.
3) Blues Union by Joe Beard & R. Earl on Audioquest.
4) Luther Allison on various labels.
5) Tinsley Ellis on Allagator.
6) Just get the Fleetwood Mac Box set, SRV Box set,Savoy Brown Box set, and the Allagator anniversary double Cd sets.
7) Someone who I just saw, Bryan Lee, Absolutely smokin !
any and all by this excellent guitarist.
This should get you started.

Any of the Mighty Sam McClain's on the Audioquest label.

Speaking of Melvin Taylor, who is great. I recently had the pleasure of seeing him live at "Rosa's", a Chicago blues joint on Armitrage. Only about 20 people in the place on a Tuesday evening. He usually plays every Tuesday and also on a lot of weekends there. He and his band were a power trio the night I saw them. Absolutely great, and a rare chance to see one of the premier blues, or any style, guitarists alive today in a very small intimate, great setting. What are you waiting for. Also, decent selection of "good" beer to dring while your there.