It is hard to ask who is the
best 
. If you had named a genre, such as the best rock
, it is easier. Just
and you are including rock, metal, classical, spannish and all other types of
s.
My person favorites... (mostly rock\blues)
Malmsteen
Vai
Clapton
Van Halen
Healy (just the way he plays guitar so well and he was
born blind)
Santana
Mason Williams (how can you not like the guy, he wrote
classical gas!)