I second Stevie Ray for blues. He's awesome. Also check out Albert Collins, Albert King, and B.B. King.
Tony Rice has some bluegrass-style blues in some songs (like "Jerusalem Ridge" off the "Church Street Blues" album
For some non-guitar oriented blues, check out Charlie Parker's album "Charlie Parker Plays The Blues", Duke Ellington's songs: "Memphis Blues", "Beale Street Blues", some good harmonica blues can be found in listening to Lightnin' Slim's albums "I'm Evil" and "Rooster Blues". Muddy Waters plays some good old school blues.
I personally love blues played on the piano. Players like Memphis Slim (esp. his album "Alone With My Friends"), Sunnyland Slim, Dr. John, Professor Longhair (New Orleans style blues), Otis Spann, Joe Willie "Pinetop" Perkins, and Fats Domino.
That should keep you busy for a while in the Blues section.
For flamenco, I'm not as familiar with the style... the only flamenco players I really know are Paco de Lucia and Al DiMeola. They're both top-notch, though. I think Paco sounds more Spanish if that's what you're looking for. Hope this helps!
[edit: just fixing a couple typos]
"You must stab him in the heart with the Bone Saber of Zumacalis... well, you could stab him in the head or the lungs, too... and the saber, it probably doesn't have to be bone, just anything sharp lying around the house... you could poke him with a pillow and kill him."
- Aqua Teen Hunger Force, The Universal Re-Monster