My favorite game. Definitely worth playing. ^^
There are some parts where things seem rather tedious, but they are worth it. And sometimes things get irritating when you can't beat a boss or don't know what to do next, but hey--if the game was a piece of cake, what fun would that be?
I think this game is pretty much just as good as Kingdom Hearts 2 and Chain of Memories, so obviously I've got no favorites between them. I guess I just like the series in general. =]