There's NO such thing as the "best guitarist of all-time" IMO.

Are they the best technician?
Do they play with the most feeling?
Best tone?
Fastest?
Cleanest?

There are a LOT of great guitarists that play in a bunch of different styles. It's just too hard to narrow it down to a couple of people.

All that said though... here's another of my favorites in the neo-classical rock genre:

_________________________
A day late and a dollar short...