Heroes 3 is widely considered the best of the franchise, but to me personally, Heroes 6 is the best. Unfortunately, it was riddled with issues ever since it came out. Connection to the Ubisoft servers via UPlay was mandatory, and you could get kicked from a single-player campaign session if you lost connection. There was no map editor/RMG for replayability, and the game balancing was not exactly good. But I loved the setting, the world, the main characters and most importantly, the creature animations were some of the best I'd seen in a long time, and many newer games from the 2020s aren't as good in this aspect.