Oldest of the lot for being the first really good one, was probably Ultima 6. Ultima 7 P1 & P2 is good as well but 8 was a control nightmare the series started to die off there. Other noteables are Ascendancy, Atrain, BadBlood, Cyber Empires, Darklands, Detroit, Dune 1&2, Lemmings, Master of Magic, Master of Orion, Oregon Trail, Savage Empire, Star Control 2(Now Open source Ur-Quan Masters), TIM 2 (already mentioned), Warlords any of them (Pain in the ass to control but fun), and Xenocide because I used to play that on a friends machine. I'm sure there are others but thats all I can think of right now.