Kefka's Tower I can't comment on because I'm still in the process of going through it.

The Northern Crater: I love this area. From the music to the visuals to the dungeon design. The monsters were pretty cool and some had some interesting battle mechanics. The only thing I didn't like was the party split-up. I just didn't see the point.

Artemisia's Castle: Another area I simply adore. "The Castle" is my favorite dungeon theme in all FF, the gimmick of unlocking your own powers was cool and some of the puzzles were very well thought out. The boss fights worked well in conjunction with the limited abilities. Overall just a wonderful final dungeon.

Memoria and the Crystal World: Pretty neat. I liked the music a lot and the cutscenes in this place were just... creepy and provided a very nice atmosphere. I did however hate the monsters. Meteor Counter? smurf you.

Inside Sin: Admittedly, this final dungeon is not that memorable. The first part was just walking endlessly with no goal in sight although I dug the fact that you uncovered bits and pieces of the minimap as you went. The Seymour boss fight is pretty nice, though, with one of the best boss themes in the series. Then we get to the city. I can't say I care much for the visuals in this area, but the enemies were awesome and unique to fight. Combat-wise, this sure felt like a final dungeon as it made you pretty much use everything you'd learned up to this point. The rotating camera part wasn't that bad either. Not worth much of a mention though since it's so short and there's nothing special about it.

Sky Fortress Bahamut: Underwhelming to say the least. You can beat it in 2 minutes and there's nothing that sticks out until you reach the elevator. I would comment positively on the Gabranth fight, but it's kind of part of the final boss gauntlet.

Orphan's Cradle: What exactly is this place, anyway? No matter, the visuals appealed to me, the music was eerie and created a good atmosphere and I really liked the normal battle theme in this area. The monsters were rather annoying though. I remember when a Sacrifice used Death on my party leader on its first turn and I got an instant Game Over. Good times.

Academia 500 AF: This place is weird. Just weird. Like in XIII, they switched up the normal battle theme to something awesome and fit for the final dungeon. Now mind you, first time I came here I was ridiculously underleveled so the monsters made a lasting impression on me, but even after I went through it again on a higher level, the monsters were still pretty nice. Proto-Behemoth is a scary foe to face. About the whole platforming gimmick, I didn't mind it. The puzzles were kind of clever, though they made the whole dungeon a bit more time-consuming than it should've been. The main thing I hated about this area is that you have to go through it twice for Monster Professor. That's just stupid.