There simply is no "best" guitarist, we all are in a little way. The art of creation using a musical instrument is one of the most amazing human endeavors. Those that consider that the instrument is used as an extension of human communication are the ones who know what I mean. Those that can create a piece of music that moves someones emotion in a way that none of the other forms of communication can, can all claim to have achieved the goal. But to try to say that a particular guitarist is the best is pointless.
Theres simply too many "best" guitarists out there.