Mickey and I use to play last chaos...
The game is still under developement though and can get old fast though.

There is Air Rivals which is a game I have been trying
but that is more of a ship based dog fighting game where you can control your pilot in the off time.


and then there is s4
but that isn't really an rpg unless you count when you in lobby.
after the game starts everyone is pretty much running around shooting each other...
In the korean version there is an Arcade like rpg mode... but that has yet to come to the european version and the korean version requires you to have a KSSN


if you check out Aeria Games they have quite a few MMO RPGs that are free.