It would obviously be FFX, they can deal 99,999 in a single hit, have Auto Phoenix on their weapons, plus can have all stats maxed and about 60k HP for someone dedicated enough (more if you sacrifice a stat like Evasion) they also have Rikku's Trio of 9999 which means they could just chuck an AoE item and do 9999 damage to the entire cast opposing them, that alone would be enough to wipe out 90% of the competition, and even if the competition manages to kill off one of their cast, auto phoenix+auto life ensures a completely dominating team.