HoMM3 is one of those games I'll still play when I'm 60 (I'm 25). I remember first seeing people play it, it was so strange and the characters seemed so out of place. There was no scale in this 2D world, where goblins are as tall as a mountain and where a mounted hero carrying armies in his pocket is as big as 1/8 of a big, heavily fortified city. It just didn't make sense, even if its setting is a fantasy world.
But after playing a little bit I realized the game is not about graphics and accurate representations of reality or even fantastic realms. It's about making decisions and speculating what the future has in the box for you, the future being nicely laid out on the map as the well known shroud called "fog of war". And in time, the initially weird graphics grow on you. You begin to learn the various buildings on the map and what they do. You even learn to name the artifacts on the map and their abilities just after revealing them.
If the campain scenarios are not enough, there's the killer feature of this game, able to provide years of entertainment: the random map generator. Choose your opponents, the size of the map, bonus start-up items and let the generator do its job. Everytime there will be a new map waiting for you and your friends to explore. Never-ending fun, I tell you.
Buy this game and honour 3DO and New World Computing, for they have blessed us with a long lasting game. Your money will probably sink in Ubisoft's deep corporate pockets, but some of it will reach GOG.com, so they'll bring us even more fantastic old-school titles like this one.