You may also want to check out Magic: the Gathering. On a high level, Master of Magic is a quite derivative game, being a clone of Civilization and ripping off MtG's spell system, especially the color wheel. But it stumbled into accidental brilliance. Tech tree in games like Civilization is notoriously bland and padded with insignificant techs. Because the whole research in MoM was made out of discrete spells, every single research step gives you something tangible! It's amazing. Another bit of accidental brilliance came from low RAM of contemporary computers. It caused the world to be split into magic planes - Arcanus and Myrror. They just couldn't manage to fit the whole world into RAM at the time!

Another single player game which can give you a lot of fun is Shandalar. It takes place in MtG setting and is an RPG game.