FFIX. Beautifull story, beautifull graphics, beautifull places, beautifull characters. Hell, everything is beautifull in that game.
But the most important thing, to me, is the feel of fantasy! You are in a magic world with many mystic places, and many misteries. I remember of playing the game and thinking "No one(in the game, until that point) know what exist outside of the Mist continent. I don't see the hour to go away and explore!". Is not like in VII or VIII, that all parts of the world are already explored and ocupied by citys.