Kenny - for driving sims, GTR and GT Legends are the way to go - top quality stuff. For a mindless drive and smash game - Flatout is a good one. I think it's been re-released on a budget label now?
As for RPGs - Morrowind and Dungeon Siege 2 are very good. Baldur's Gate 2 is an epic, though it does look a little dated now. If you want a more up-to-date (as in scenario) RPG, Fallout Tactics is a welcome alternative. Straight-forward experience hack games would include Diablo 2 and Sacred.
For FPS - Battlefield 2 is the current daddy.
D.