Great choices, everyone! I'm going to add the following-
Two from Muddy Waters
Live at Mr. Kelly's
Folksinger
Jimmy Rogers-Chicago Bound
Rogers was guitarist in Muddy Waters' band, and cuts this disk as bandleader with Muddy Waters playing rythmn guitar and Little Walter on harmonica.
Two Chess Records best ofs, available on LP
Howlin Wolf aka Chester Burnett
Little Walter -Boss Blues Harmonica
Btw, did you know there are two Walter Hortons? Little Walter, who stood 6'5", and Big Walter Walter Horton @ 5'9". Go figure!
Albert King-Thursday Night in San Francisco
BB King-Live at the Regal (already mentioned and worth a double shout-out)
Magic Sam-West Side Soul
Mississippi Fred McDowell-I Don't Play No Rock n Roll
If you are interested in acoustic, country blues, try these-
Mississippi John Hurt-Avalon Blues
Sonny Terry/Brownie McGhee-Backwater Blues or Midnight Special. Both really good.
If you want to try blues vocalists, these are really good-
Helen Humes-The Definitive Black and Blue Sessions
Big Mama Thornton-Ball n Chain
Jimmy Witherspoon and Jay McShann-Going to Kansas City Blues
Roosevelt Sykes-Dirty Double Mother For You
Joe Williams and Count Basie-Everyday I Have the Blues
Here are some "white boys who can play the blues"
Story of Them Featuring Van Morrison
Captain Beefheart-Safe as Milk
James Thackery-Essential James Thackery
Stevie Ray Vaughn and Double Trouble- Texas Flood (another double shout-out)
Jimmie Vaughn-Roomful of Blues
King Biscuit Boy-Gooduns
Finally, jazz and rythmn and blues-
Duke Ellington-Blues in Orbit
David Sanborn-Here & Gone
Louis Jordan-Number Ones