The best final battles are:
1. Final Fantasy 8 : it was long as all get out but the music and setting get you so pumped up after each phase you defeat, your adrenaline will be stuck in overdrive!
2. Final Fantasy 7: it was long and a bit complicated, which didnt sit well with me. but the ending movie is better than FF8 which is on a bit of the sweet and cute side.
3. Final Fantasy 10 and 12: it's a tie. they were just so easy. final fantasy 10 once you get past the first phase of Jecht you could do the rest with your eyes closed. though the music does get you pumped. final fantasy 12 you dont even have to lift a finger if you set your characters up right! which TOTALLY takes all the fun out of the game, since FF is meant for you to think on your feet. especially if you have it in "active" mode.