Unless I'm only playing as the Joker on one platform again, I'll leave the arguments over the "superior version" to people who have the compulsion to pour over side by sides on lens of truth. There's got to be exclusive content or something needs to be totally broken on one side for me to take console comparisons seriously. That's just my opinion of course.
Joker content was a nice addition. I played both versions, but kept the 360 version. They play exactly alike, but the aliasing on the PS3 version was always noticeable to me. Scarecrows eyes also had this wierd pixely flicker to it, as well. Colors were, however, more vibrant on the PS3 version.
I'm just going to stick to what I've done for most of this gen. Exclusives on the respective consoles, and multiplatforms on 360.