Hmm, if you're not an Atlus fan you may be a bit out of luck. Non-Atlus RPGs I can think of off the top of my head are Mario & Luigi - Dream Team, Tales of the Abyss, Crimson Shroud (Matsuno e-shop pen-and-paper-esque game), and Heroes of Ruin. There's a ton of good Nintendo games though, Mario 3D Land is pretty ace in particular. Kid Icarus I didn't like but a lot of people seem to - the game has a TON of content and great production values, but the controls just did not work for me.
Vita may work out well for you too, since there are a few FPS games already (though I don't know how good they are), and can output some awesome graphics.