On personal drama, we all know that FF6 and 7 slammed us over the head the most. As for uniqueness, same thing. In scale, it was probably 5, with three worlds and all (more like 2.5 really).
I still think 4 was on the biggest scale. It had the evil empire, the hero's catharsis, wars both in backstory and involving you, the moon, and one of the few high fantasy stories to actually work as a game.
The only problem was the final boss who didn't really have a story except for the puppet master.