Ps3 hands down
1) Higher resolution textures due to less compression
2) Most people who want Final Fantasy will have already bought a ps3.
3) Low sales for rpg's on the 360 thus far.
4) Japan has the game now and it has a 2 million head start by the time it comes out stateside.
5) The fact the Versus is still exclusive is what is selling a lot of people about the ps3 version.