I just finished Grandia III, and I must say that "a work of art" aptly describes the game. Unfortunately the banal plot manages to drag down what would otherwise be a truly amazing rpg experience. Game Arts seemed to decide to take every major plot element of every previous RPG they've made and mash them together, making a whole that is definitely less than the sum of its parts. Also, I spent the entire game wanting to punch Alfina in the face. The worst thing is that I think she's probably even worse in the Japanese version, where I'd expect her voice actress to be much higher pitched and refer to herself as "atashi."
Everything else, though, is golden. The graphics are gorgeous, the art direction is brilliant, the dungeons are competently made, and the combat system is a refinement of a system that was already my favorite in the genre. If you're looking for an RPG that carries its weight on pure gameplay, this is the one for you.