Well, gosh, where to begin. Based on the folks you have been listening to, you seem to gravitate toward urban/Chicago-style electric blues (see item #5 below). I will, however, throw out some names that represent a number of styles, since you may enjoy hearing more than one approach to the blues.
1. Early 1920's and 1930's blues (almost exclusively women): the best-known would include "the Empress of the Blues" Bessie Smith, Ma Rainey, Ida Cox, Alberta Hunter, Sippie Wallace, and Victoria Spivey.
2. Mississippi Delta / country blues: Blind Lemon Jefferson, Robert Johnson, Charlie Patton, Huddie Leadbetter (Leadbelly), Son House, Mance Lipscomb, Big Bill Broonzy, David "Honeyboy" Edwards.
3. Piedmont blues: Blind Boy Fuller, Mississippi John Hurt, Sonny Terry & Brownie McGhee, and Cephas & Wiggins.
4. Early urban blues: Leroy Carr, Roosevelt Sykes, Tampa Red, and Sonny Boy Williamson.
4. West coast "jump": Joe Liggins and the Honeydrippers, Roy Milton, Charles Brown, Percy Mayfield, T-Bone Walker, and Ray Charles.
5. Chicago/contemporary urban blues: Arthur "Big Boy" Crudup, Willie Dixon, Muddy Waters, Little Walter, Otis Spann, Elmore James, Howlin' Wolf, James Cotton, John Lee Hooker, Buddy Guy, Junior Wells, Lightnin' Hopkins, Clarence "Gatemouth" Brown, Albert Collins, Albert King, Professor Longhair (Henry Byrd), Johnny Copeland, Luther Allison, Robert Cray, Stevie Ray Vaughn, and -- of course -- the "King", B.B. King.
6. British and American blues bands: John Mayall and the Bluesbreakers, The Yardbirds (later Led Zeppelin), Eric Clapton, Paul Butterfield Blues Band, The Fabulous Thunderbirds, George Thorogood and the Destroyers, Roomful of Blues, Canned Heat, Siegel-Schwall Band.
7. Contemporary blues vocalists: Koko Taylor, Esther Phillips, Etta James, Katie Webster, Marcia Ball.
There are many, many lesser-known blues artists that you may also thoroughly enjoy. To learn more about the blues, I recommend an inexpensive but enjoyable and informative book ($20), "Rhino's Cruise Through The Blues", written by Barry Hansen, and published by Miller Freeman Books. The book is sold by Barnes & Noble and other large book chains, and can also be ordered from Amazon.com.
