9 is the newest one in the series(Besides the Japan only mmo), and it was made with newer players to the series in mind, much like Fire Emblem Awakening was. It's for NDS, so go ahead and pick up a copy, or at least look into it.

If you like FF, chances are you'll like DQ as well. It's made by the same company, Square Enix, And it was Enix's rpg competing with Square's Final Fantasy before the companies merged