Xbox 360 is definitely the best. (I'm also NOT regurgiating what people say, I've downloaded the demo for Xbox dn PS3)
Due to the PS3 being a 1080p console and thus having better graphics than the Xbox (A 720p console). The colours look a bit washed out, however than can be fixed in TV settings and again, the graphics do look better on 1080p console (as they should)
The PS3 suffers from terrible frame rate skips during cutscenes whereas the Xbox is completely smooth.
The PS3 has extremely terrible shading. On the Xbox the shading is a smooth gradient that looks natural whereas the PS3 has a more "blocky" style shading which looks awful.
It then comes down to preference of controller and which console you feel moe comfortable playing, though the Xbox doesn't feel worse than the PS3. After I downloaded the PS3 I didn't feel any different once I adjust my controls. However, once the full game comes out and will make use of the d-pad, we'll see what is the best to use.
Other than that, meh. I think Xbox is best