Out of the ones that i have played (the ones that were released in the west), Radiant Dawn is my favorite closely followed by Path of Radiance. Reason are basically the really good story and characters. I also think that the gameplay is the best of the series (of the games that i have played).
Playing: F1 2016 (PC), Uncharted: The Lost Legacy (PS4)
Watching: Hajime no Ippo, Attack on Titan (4th time)
Upcoming purchases in October: