If TWEWY counts, then obviously listing that because it rules (but I'd be surprised if it counted)
Rock 'N' Roll Racing: Seriously, this is some old-school retro ***-kicking racing right there. Sweet soundtrack too. It's a SNES/GBA game so go check it out somehow, really.
Front Mission 3: NOBODY seems to give this sweet game love outside of the forum for it at gameFAQS, and even then it's kinda limited.
Vanguard Bandits: pretty much ditto as FM3
Mech Commander series (being Mech Commander, Mech Commander: Desperate Measures, and Mech Commander 2): All of these games were pretty sweet PC games that have pretty low system requirements in this day and age and are just a blast to play.
Red Faction II
007 Nightfire