Re: best metal guitarist (your opinion)
It's impossible to narrow it down to just one when so many have influenced the masses. Richie Blackmore would probably be the best however since he's cited by so many old and new school guitarist as a prime influence. Tony Iommi, Michael Schenker & Ulrich Roth were also around in the formative years and get loads of praise too. Everything else simply breaks down into your favorite. The guitarists who've influenced my playing more than any other are:
Dave Murray (Iron Maiden)
Eric Brunley (Novembers Doom)
Gregor Mackintosh (Paradise Lost)
Daniel Cavanagh (Anathema)
Glen Tipton (Judas Priest)
James Murphy (Death, Cancer, Obituary, Testament, etc...)
Yngwie Malmsteen
There are TOO MANY overrated guitarists to name. Specifically those who magically became "gods" after their deaths. Dime is one in particular that gets way more praise than he should. All he did was trill, Dave Murray has been doing that in Maiden for 30+ years and hasn't received the same recognition. Dime was ok for what he did but he was no genius.