Both KH 1 and 2 has Sephiroth, and I hope they don't have him again. Who would you like to see as the new super boss?

For old school FF fans Chaos could be fun, even though i didn't beat one I'd enjoy seeing him.

Moreso I'd like to see Kefka. That would be an awsome fight.

Also Kuja would rock. Fight him in regular form then Trance.