Oriental Empires. Always gave me the impression of being kind of a shonky Total War knockoff, but actually, despite taking a lot of elements from Total War and especially Civilization, it makes a good first impression and has a couple of crucial elements that set it apart (recruitment, population/food management, semi-autoresolve combat system). For better or worse, it eases you in by making you play as one of the easiest factions first, and I'm finding my first game to be a lot less overwhelming than, say, my first GalCiv 3 game or Imperator game. It's drawn me in, and I'm already looking forward to playing as a herder faction once I unlock them, and then as a nomadic one from the Genghis DLC.