I'm conflicted.
I've got all systems, and a gaming rig with a GTX 275. I'm in Canada, so my choices are the following:
1) PC version (Steam) for $50 USD
2) PS3 version for $38.83
3) 360 version for $38.83
I played all demos. PC version runs flawlessly at 60fps with 4xAA, but without PhysX. 360 and PS3 versions look considerably worse, running at 30fps, and definitely having worse textures (readily apparent looking at the checkered pattern on the Batsuit). The PS3 is the worst looking one, looking almost identical to the 360 version, but with no AA (not super noticeable overall), and a bit of tearing (can't see any tearing in the 360 version).
So far, I'm leaning towards the PS3 version, mainly for the reduced price, but also the Home rewards which seem amazing. I'd go with the PC version, as it feels and looks a lot better, but I'm afraid of the game not being worth keeping, so at least with the console version, I can trade it in quickly enough and hardly lose any money at all.
Oh, another bonus to the PC version is the likely ability to mod Batman's eyes to make them white. :lol