I'd recommend the following...
Dune 2 (RTS)
Sword of the Samurai (RPG-ish)
Civilization 2 (Strategy)
One Must Fall (Fighting)
Princess Maker 2 (beats me)
Syndicate (Strategy, I guess)
Red Baron (flight simulator, WWI)
C&C: Tiberium Dawn (RTS)
Moonstone (beats me too)
Wasteland (RPG-ish)
There's a lot of great games here...
at Abandonia.