The PS3 is by far the superior system, not only is it the best Blu-Ray Player (the only one I know of that has firmware/software upgrades and will be Web 2.0 ready in March) but the controller layout is better, games are cleaner, and of course Gran Turismo, if it ever gets released.
I've also owned a 360 but that lasted for a month. And i bought a Wii for the wife (Wii Fit...ya i know) its fun for parties.