I happen to own both a PS3 and XBOX 360. (But the 360 has been sitting on a shelf, collecting dust for over 4 months now...)

So, I'll be grabbing the PS3 version. I have three reasons for this:

1. Ever since FFVII (and even though I dislike giving this game any credit...), Final Fantasy games have mostly been on Sony. I suppose it would be breaking tradition to play it on the 360 all of a sudden.
2. I would've bought it as soon as possible if it came out for PS2, like they originally planned long ago. I don't care about graphics, not to mention we could've gotten it a LOT earlier.
3. The PS3 controller is far more manageable than my XBOX 360 one. I have the charger for my PS3 controller, so I don't need to go find batteries when it goes dead. UNLIKE the 360, which has the battery issue, and that's a real struggle. I was playing SO4 a lot, and faced the "The Controller has lost power" or something message. It was annoying, because I always seem to be out of AA batteries... >_> So screw that, and screw multiple disc changing.