Heres a few oldies... that, most likely, none of you would have even heard of.
Heavy Gear 2, Battlezone 2, Tachyon: The Fringe
Old games but great. BZ2 and TTF run on 7 (suprisingly) but HG2 needs Windows ACT installed to run.
HG2 took up endless hours of my time. Numerous weapons to choose from (Forgot just how many, but I think its 75+) and numerous mech's to use (although, the only diffrence between any of them is the design. Weapons, stats, perks and flaws are all customizable) made for a excellent time waster. The only bad thing about this game is that its control configuration... is kinda weird. You can modify it, but you'd have to change numerous controls.) Just to show how weird the controls are, all of the important movement controls are all on the numberpad.
And suprisingly, BZ2 still has a lot of people making new patches and mods for it. The most recent, unofficial patch, was released on 6-9-11. I haven't seen any games up though proably because I'm still running on 1.2 (instead of 1.3 PB 6 R2) but their should be a couple games up for the newest version.