Kingdom Hearts Final Mix, FFX International, or any of those special editions didn't contain any "real endings" - they just added some bonus bosses, or new modes (Chain of Memories in 3D).
FES is basically -the- version to get, it tells the consumer that they never finished the game on time. It's not an "alternative" ending, it's -the- ending, the one the story had in mind.
Ichirou - I am without a doubt a diehard Persona fan. I just don't flaunt it like a schizophrenic Himuro. Persona 3 isn't that good.