Since the official Dungeon Keeper 3 never saw the light of day, several indie developers stepped in to fill the void. If you are looking for a modern experience that captures the "it's good to be bad" spirit, these are the top contenders:
“Dungeon Keeper 3 is not in development. We’ve moved the team to other projects.” dungeon keeper 3 game
The Rise and Fall of Dungeon Keeper 3: War for the Overworld Since the official Dungeon Keeper 3 never saw
Some notable features of Dungeon Keeper 3 include: dungeon keeper 3 game