Well let's chat about the Final Dungeons of FF's shall we?
To me a game needs an impressive Final Dungeon in order to be fun and epic. If the Final Dungeon is lame, short, and easy the game is totally ruined for me. It's also got to have some good tunes to listen to as I stroll through fighting the final challenges leading up to ultimately saving the world.
As far as Final Dungeons are concerned I found many of the FF's to have enjoyable Final Dungeons, and some to be less them impressive.
Of my all time favorites FF III's Crystal Tower stands out. It has a great song to listen to as I climb the tower and fight monsters.
While the dungeon could use more in the way of puzzles or bosses it was still enjoyable, and was an epic trek towards the final battle.
FF IV was a unique setting for a Final Dungeon and had a nice long trek of fighting bosses and collecting gear to do up until the final battle.
FF VI was a tower made of pure chaos fitted with bosses and puzzles that needed to be overcome by 3 parties before you can take on the final battle.
As for bad Final Dungeons, I would have to say FF X wins that one hands down.
It didn't have a good tune to cruise through. It had a single lame boss fight with a major villain which just ended all of a sudden. There was no puzzles, it was short and could be walked in like 5 minutes. And it lead up to a final confrontation which was epic lame. "Oh hey bad guy! Let's fight!" It didn't build up any suspense and pump me up enough for the final battle, and ultimately let me down.
FF XII's was a short little sky fortress that was about 2 rooms big. While the ending sequences were good, the build up was terrible. "Oh hey guys REVOLUTION!!!" I ran past all the enemies because there was no point to fighting, it took me about 3 minutes before I had cleared the Final Dungeon. I will give the game that it had a nifty cut scene before the Final Dungeon, but once inside it was a let down.
Well then! Let's talk about the Final Dungeons and what you like in a Final Dungeon!