Heroes of Might and Magic 3 (and its domestic clone, Heroes of Might and Magic 3.5 (WoG)), due to the failures of games that are not worthy of being called Heroes of Might and Magic 4...
Hey, there's no need to bash the fourth installment! If you don't like it, don't play it! It's just interesting online when you're facing a real person, not a dumb AI. It's beautifully made, and the idea is good, but not fully realized. Ah, if only the source code were freely available...
I myself started with "part two" and gradually moved on to "part three." I consider these parts to be great and the most interesting, but "part four" also has a place in my heart. After that, something went wrong. Either it didn't work out at all, or it worked out crookedly. In general, it didn't work out. Maybe the other parts aren't any worse, but I played them little and they didn't grab me.