I think they should make one gigantic Final Fantasy in which all the main characters and final bosses of each FF game are somehow connected and help each other out during the story.
...No, nevermind, I don't really think that, that'd be ludicrous. However, a fighting game with a lot of the main characters and final bosses would be sweet (even better if it's done SSBM style), and little (if any) new characters.
But we all know that will very likely never happen.
P.S. Joel, I refuse to clcik.