Yu Yevon was a story battle seen loads of times in FF games (and probably other games too). The only difference was that it was imposible(?) to lose not win.
I liked V's final place, it looked pretty cool starting of as a mixture of places then being this sureal-ish type place. VI's was nice that you had to use practically all your people, VIII's was quite interesting as you can try it with hardly any skills if you want (which I didn't) as much as I like VII nothing really seperated it from any other "dungeon" area in that game - thankfully I like them enough for it not to matter.