Cheat: Auto Leveling
One of the gorgeous designs of Final Fantasy XII's gameplay is in the semi-automated design of the Gambit System.
By assigning a series of if/then commands to your party, you can engage in a battle without lifting a finger, but still have a gratifying sense of accomplishment in winning the fight. Now imagine adding a foe that infinitely spawns lesser foes and with you having the ability focus just on those weaker targets. Set your gambits right, leave your PlayStation 2 alone for two or three days, and voila, Level 99 party.
How's that for your sense of accomplishment?