The greatest blues guitarist to ever pick up a guitar/draw breath... two words. Roy Buchanan
His vocals weren't the strongest, but he could make a guitar talk... bark like a dog... meow like a cat. Yup, he could melt the music right into your mouth...
I saw him twice in concert, and he's the most awe inspiring, technically awesome guitarist I have ever seen... and yes, I have seen Jimmy Page, Jeff Beck, Eric Clapton, Robin Trower and Hendrix live in concert