Haven't played IU. So far, ToV is the best jrpg I've played on the 360, and one of the best games I've played this gen. However, I'm a huge Tales fan, so the game appeals to me, in particular.

I didn't like Eternal Sonata or Lost Odyssey, though I respect them and their fanbase, and certainly see those game's appeal.

I also want to add that Tales is getting introduced to a whole new fanbase because of its availability on the 360. I only wish it were available across all platforms, because I think the game could capture the hearts of thousands of new Tales fans. It really is a fun game, and I'd give it to any gamer I know, confident that they would be absolutely charmed, assuming they'd played farther than 3 hours in.

   I would be willing to bet that Tales will head over to the PS3 if Eternal Sonata does well after making the jump.  I think that Eternal Sonata will actually sell at least slightly better on the PS3 then on the 360 and from then on all Namco Bandai games will be multiplat this gen.  I don't think a lot of people expected the PS3 to pick up steam this fast and made decisions based on the gimpy 2007 PS3 instead of the much stronger 2008 PS3.

    That said Namco is a weird company sometimes.  I mean they looked at the last gen and put the first PS2 gen tales game on the failing Gamecube only (the only tales game I've played thus far) so who knows.  Maybe they'll make a new tales for the PS3 like they did with the PS2 last gen instead of porting this one.

   Odds on ToV on the PS3 in Japan 85%, odds of ToV on the PS3 in the US 70%.

   The only 360 RPG I really enjoyed is actually Mass Effect, a super awesome game someone else pointed to earlier.  If you have both I'd get it on the PC though (the inventory system and graphics alone make it worth paying a little more then the 360 version).  I think I would semi enjoy ToV if I still had a 360 like I semi enjoyed the Gamecube tales.

   For Lost Odyssey and Blue dragon make sure you rent before you buy unless you find them REALLY cheap.  I played through about the first disk of LO and it was pretty awful, I didn't even last more then a few hours in Blue Dragon, it was even worse.  Eternal Sonata is pretty great though, I'd have played through the whole thing if I hadn't heard it was coming to the PS3 with new characters and added content.  

 Enchanted Arms isn't even worth a second look.  Pretty awful on both the PS3 and the 360, was just the first RPG of the gen, those are never ever good.

   If you have a PS3 though I bet ToV will be out for the PS3 soon enough (prob a year, as I said above), Eternal Sonata is already almost here, Lost Remnant is coming to PS3, Infinate Undiscovery got some ugly reviews and theres disgaea 3 which is fun now and Valkria Chronicles in a month which also looks pretty good.  The Xbox 360 number one JRPG thing is fading pretty fast now that the PS3 is picking up steam week by week.

   If you don't have it yet get Persona 3, that is the best next gen era JRPG by far (and its on the PS2 which I'm positive you have).  That game is better then all the 360 and PS3 JRPGs combined.  With the FES version its at least 100 hours of pure goodness.