I've never owned a 360, so I sure which games it has. But for starters, there's always the other games in the Western series you mentioned: Fable III, Skyrim, The other Dragon Age games, etc. There's also Fallout III.
If you're looking for something more Japanese, I've heard good things about Magna Carta II. Haven't played it myself.
Also, I know you'd like to stay away from action, but you could try whatever Tales game has a 360 version (Vesperia?). They're in a league of their own. The stories are usually pretty good too--mostly because the character design is top-notch.
Sadly though, if you're looking for good traditional JRPGs, you either need to look to older gen consoles or hand-helds.