FFX has one of the few endings in the entire series that were actually properly done. Most of the games had those diabetes-inducing "oh yeah we beat the giant space monster now everyone is totally happy 4eva" kind of endings that just made me wanna puke.
Er...which? Certainly not FFVI-FFIX (the main ones I've seen), all of which carry echoes of which are bitter sweet in places, or are left open-ended.