Dungeon Keeper
Populous
Abe's Abyss/Exodus
Warzone 2100
Worms Armageddon (Worms 3D is some kind of "f-ed up")
Rollercoaster Tycoon (again, the new 3D sequel is BAD)
Monkey Island! (can't blieve noone mentioned it at least a remake of the old games so you dont need an SCUMMVM)
Rent-a-Hero
Zazarah [not so old though](reminds me of finally buying the full game, should be available at low budget price by now )
Wiggles [also, not so old]
Giants
Oni
Half Life - Gunmen
Startopia
Black and White (B&W 2 was kinda disappointing)
Delta Force
System Shock
Deus Ex (the sequel isn't good, hoped for smth better)
Homeworld
Klingon Honor Guard
"some game I cant remember the name of because I never bought the full version and cant find the demo anymore"
Caesar 1-3
Recoil (3dfx pawah)
MDK

and lots of others