Most people who have both consoles currently would take the PS3 version over the 360 (unless of course, they have friends buying 370, etc) due to many things the PS3 does better. (Fewer discs, more processing power, if done right, PS3 versions SHOULD look better, etc)
I own both and will be getting the 360 version. I'd rather be getting it on pc but I'll have to wait for that. I bought my PS3 as a BR player and for a few exclusives. Anything that gets released on both I buy for 360. My preference really comes down to the 360 controller being more comfortable to hold. I have arthritis in my hands and I can only use a PS3 controller for a short time before it starts to hurt.
http://thebulldogs.com.au/media/logo_2010.png - 2012 NRL Season: Minor Premiers. Grand Final runners-up. Bring on 2013.