*Chocobo Races: I've never been much for gambling but this might be good if we could race our own birds and train them in our stables for that purpose.
*Hot & Cold: This was insanely fun in FFIX and I would hope the guys avoid the mistakes made in XI.
*Battle Square: A gauntlet-type battle would be interesting if the rewards are good.
*Shooting Coaster: This might work if Garlean aircraft can be fitted into the equation.

Ideas? Throw whatever you have at the wall and see what sticks.