PS3's turn-based RPG selection is pretty thin, and while the games have their strong points, they also have some serious flaws. If you're looking for a turn-based RPG that's strong in every aspect, you might want to check out the PS1 games you can download off of PSN.
Alternately, tell us more about what you value in an RPG, and we might be able to recommend a current gen game that scores well on those values.
I think that Ni No Kuni is not turn-based, and that I'll eventually get around to playing it after I finish my current projects with FFXIII.
And incidentally, I don't recommend FFXIII for you. It has great scope for strategy, but is extremely limited in terms of personalizing your characters (you control the order in which the characters learn stuff; what they learn is predetermined).