FFII is my favourite in the series, because of the clever stat system, the difficulty (no other FF had such large and difficult dungeons) and the plot. I don't think there was a lack of hard bosses. The optional bosses in Pandemonium kicked my arse most of the time, especially Satan. I also found the last boss quite hard.

But the hardest part of the game, and the only thing that sometimes frustrated me, is trying to find the next location. You have to cover huge distances every time, with hard random encounters at every step.

Still, love the game.