I personally find Tales of Vesperia to be the only really good RPG for the 360 so far (but by really good I mean GREAT)...Blue Dragon and Lost Odyssey follow the traditional formula too much (which you may actually like), but the story for Blue Dragon is pretty much non-existent...Eternal Sonata is pretty and has an amazing soundtrack (Motoi Sakuraba <3), but the story is garbage and the gameplay overly-simplistic...Infinite Undiscovery has a lot of great ideas poorly implemented, but it's an okay ARPG if you find it cheap...I haven't played Last Remnant, so I can't give any real insight into it besides friends of mine saying it's a technical mess (load times, texture ripping, etc)...
Tales of Vesperia is definitely worth it though! =D