FFXVI was fun. Could have used some more gameplay depth, but had a great story and compelling characters, and very tight combat. It just got fairly generic to play later on as the combat did not evolve much.

For XVII, I'd like to see more depth of customization and more RPG elements. And the return of playable party members. I think they try to do something different in each main FF entry so I also hope to see something new and exciting.