As long as we are talking about old games that are still the gold standard, how is it possible no one has recreated the giant-god-monster and city management game Black and White yet?! That game was fantastic, and its premise so solid. It seems ripe for replication in more contemporary engines.
Peter Molyneux. Will Wright created SimCity and The Sims. Peter Molyneux created Black & White and Populous (and Fable, and Dungeon Keeper, and Theme Hospital, and honestly he had a really fucking good run until he disappeared up his own arse and then returned as a grifter).
I never played Theme Hospital, but I spent so much time on the rest of those… Populous was so much fun. B&W was similar conceptually, but the kaiju aspect made it feel different. Slapping imps in Dungeon Keeper was fun all by itself, let alone the rest of the game. Fable was fine but I was more into other stuff at the time. I don’t think I played very far into it.