Looking back (and ahead) I think all 3 manufacturers have pretty strong lineups with some definite classics between them.  So which do you think is best (and why?)?

Also, for the purposes of comparison I kept "1st party" to the IP level (sorry Mass Effect 1 fans) which also leaves out licensed IPs (sorry DC MMO fans), and I also decided to leave out purer adventure games (sorry Zelda fans).  Also kept it to home consoles (to avoid the DS Poke-rape) and left out VC/XBO/PSC digital reissues.  Let me know if there's anything I missed...

Xbox 360 (Microsoft Game Studios)

• Blue Dragon (Mistwalker / Artoon) 2006
• Lost Odyssey (Mistwalker / feelplus) 2007
• Infinite Undiscovery (tri-Ace / feelplus) 2008
• Fable II (Lionhead Studios) 2008
• Fable III (Lionhead Studios) 2010

PlayStation 3 (Sony Computer Entertainment)

• Folklore (Game Republic / Gaia) 2007
• White Knight Chronicles (Level-5) 2008
• Demon's Souls (FROM Software) 2009
• White Knight Chronicles II: Awakening of the Hero (Level-5) 2010

Wii (Nintendo)

• Fire Emblem: Radiant Dawn (Intelligent Systems) 2007
• Super Paper Mario (Intelligent Systems) 2007
• Tackt of Magic (Taito) 2009
• Pokemon Mystery Dungeon: Blazing/Luminous/Stormy Adventure Squad (Chunsoft) 2009
• Xenoblade (Monolith Soft) 2010
• The Last Story (Mistwalker / AQ interactive) 2011

Nintendos is unfair unless you live in Japan. Xenoblade, The Last Story (isn't even out yet), and WKCII haven't even hit the west.

Going with 360 based on your list.

 Super Paper Mario isn't an RPG.

 But er, going off that list, I'd go for 360, albeit I've not played Demon Soul's which is probably the only worth part of the PS3 list anyway.

Well, it's not just stuff out now, but future lineups I'm considering.  Pretty sure Xenoblade, WKC2 and The Last Story will come to the west too.

I've played it, it is.  It's an action RPG.

MS, no question. Fable II imediately makes this true. For FF fans, I suppose Lost Odyssey would be that point . . .

Demon's Souls is the second best game overall though.

F2 > Demon's Souls > Lost Odyssey >>> all else on the list. Which shows how low the first party RPGs are in quantity this gen.

By the way, you forgot Mass Effect 1. Add it.

I would say Microsoft. 

-Some of Nintendo's RPGs are only in Japan

-Sony just doesn't have as many.

You do hava a point though. The DS would kill in RPGs

Definitely Microsoft.

And Super Paper Mario is in no way or form a RPG   O.o

I haven't played it, but I thought Valkyria Chronicles was an RPG. or was it a strategy game.

Take it from someone who's completed the game, yes it is.  In fact, it's more of an RPG than a platformer, the emphasis is squarely on grinding, subsystems and exploration (just like Paper Mario 1-2), only now everything's realtime.