Alexi Laiho (Lead gutarist of Children of Bodom) for technical skill
He loses all those points due to being an insufferable narcist though. And he's gotta stay away from the damn mic.
http://www.metal-archives.com/artists/Dan_Swan%C3%B6/433, contributed to so many projects and I love the range of his vocal talent.
Ah yes, definitely an underrated musician, much like Roy Z.
For me:
Vox:
http://www.youtube.com/watch?v=tVP4CqJ7SK4
http://www.youtube.com/watch?v=3T-q5B3x4lk
http://www.youtube.com/watch?v=1yChhCxtHHI
http://www.youtube.com/watch?v=VtShcJB1Exs, whose solo work is infinitely superior to crappy Maiden
http://www.youtube.com/watch?v=I9YlTBEBwIQ
Drums:
http://www.youtube.com/watch?v=xRyl_p1z9Nw
http://www.youtube.com/watch?v=Nijj4nRi9PQ
http://www.youtube.com/watch?v=CLzBo-RoZVY
http://www.youtube.com/watch?v=UhP4lg28fs0 (everyone should see this, it's insane)