Heroes of Might and Magic III is one my all-time favorites in the fantasy RTS genre. Its enormous scale (the number of campaigns, scenarios and the huge amount of player-created content, downloadable in the WWW) is overwhelming, its strategic depth allows years of fun, and the 2D-graphics with the great soundtrack creates a great atmosphere, to make you feel immersed in a realm of magic, honour, glory and fairytale.
In 2003, I bought this game the first time, years after its initial release.
In 2005, I bought it the second time.
And now, in 2009 and although I got HoMM V some days ago via Steam (after surprisingly noticing that the fifth part runs rather well on my netbook), I purchased the HoMM III a third time it, here at GOG.
Now I am really happy. :)