Coroner - Ron Royce (aka Broder). His finger work, speed and scales are simply peerless, without being Myung-ishly self indulgent.
Phil Dakin - Dead Brain Cells. A gem of a band from the late 80's. Awesomely good player.
Blacky - Voivod. Great tone, great chops and an integral part of the Voivod sound. Immediately recognisable.
Dan Lilker - Nuclear Assault. Game Over is a bona-fide classic.
Rob Yahn - Dark Angel. Played on Darkness Descends. A wonderfully nasty album.
Rob McKillop - Exodus. Played on all their best releases. Great live player.
Greg Christian - Testament. Great finger player when most 80's thrashers were picking. Triplet speed good enough to keep up with Skolnick.
Martin van Drunen - Pestilence. Before they became full on death metal, MvD nailed the bottom end for this vastly underrated Dutch band. Currently a travesty to the Pestilence name !
Paolo Jr - Sepultura. Matured greatly and peaked, IMO on Beneath The Remains and Arise.
Rob Fioretti - Kreator. One of the best of the European Noise Records bands. First four albums absolute classics.
There are many, many more, but these guys come to mind mainly because they still turn up when I hit shuffle!