Shadowman and Master Darque
Rai from the Future Force
Black and purple outfit Ninjak's
Solar the Destroyer and Solar: Man of the Atom
Turok Dinosaur Hunter
Archer & Armstrong
Check out how cool these icons can look with the right desktop wallpaper:
UPDATE: The original site I found these icons on is down (seemingly for good) but the good folks at Valiantfans.com also have the icons. So head over to their page on Valiant Comics computer icons to download them.
UPDATE II: I've recently learned that these computer icons were made by Steven Louie of Brooklyn for the PC. And that Steven submitted them to Valiant, won a Gold logo book and had the story published in the editorial section of the comics!