"Most versatile guitarist" is not necessarily the same as "favourite", or "greatest" - and it's a harder category to judge than those two. Why? Because many professional pickers can do all sorts of things outside the genre for which they're best known, but rarely reveal this except at informal jam sessions, which few of us are privileged to hear.
But on the evidence of my own ears, there's one obvious contender no-one seems to have mentioned yet:
After decades of neglect, Davey is finally getting the recognition he deserves, now that his classic recordings (and some amazing tapes of after hours sessions) are becoming available on CD.
If you haven't heard any of them yet, your education as a guitar afficionado is still incomplete.