1. Final Fantasy X
Ironically, however, the most enjoyable battle system in the series' history is purely turn-based. For the first time since 1990's Final Fantasy III, the realtime strides the series made for installments IV through IX were dumped in favor of a battle system that stops and waits for your every command.
Does that sound dull? It shouldn't. The battles are perfectly executed. Though there are only three combatants, you have access to any and ever member of your party via instant hot-swapping. The turn progression is outlined on the right side of the screen, allowing you to plot out your moves with utmost precision. Bosses require tricky handling and foresight. Getting the better of them is always a challenge, and the super attacks and summoned monsters, often overpowered in other games, are anything but overwhelming - they're more helpful tools for the fight.
The game has the full complement of abilities you'd expect from a Final Fantasy, and you can take your characters down different paths on the addictive Sphere Grid leveling system to unlock the skills you choose - once you've run through the proscribed paths laid out, it's pure freedom; the first game in the FF series to appease the "but all the characters are the same now!" crowd while still retaining the traditional class-based personality in character design and function.