Like many other people here, I have played a ton of HoMM 3 in particular. One under-appreciated aspect was the scenario editor- as a kid, being able to make my own maps, challenges, and hidden secrets was a feeling of immense power.

I still play HoMM 3 several times a year- play a few maps, use my normal terrible strategy of one super-powerful hero and a few heroes to ferry troops around, and enjoy the nostalgia.