I don't know about best, but my favorite has to be Buddy Guy. I saw him in a live performance, and besides his high NRG guitar pyrotechnics, he has a smile and stage presence that could light up Montana. BGs version of "Mustang Sally" is the most incredible I've ever heard. Eric Clapton once referred to him as "the greatest blues guitarist in the world"-- I agree. Craig.
Best musician in the world?
A question posed in another thread, in my view, although musicianship is hardly a sport to be measured as such, the most universally prodigious musician is probably Shawn Lane. He is definitely the world's most phenomenal/inimitable electric guitarist. And he is a world-class pianist and saxaphonist as well.