I didn't get that 5th anniversary edition (as the GOTY edition is identical to the 5th anniversary edition and I don't see the need to purchase the 5th anniversary edition when I have the GOTY edition), but as far as technical superiority goes, the PS3 version of Oblivion runs at a higher resolution (a native HD resolution of 1280x720 as opposed to the 360's sub-HD resolution), has a farther draw distance, better texture filtering, and shorter loading times. The only bug the PS3 version of Oblivion has that the 360 version doesn't is the vampire cure bug and it lacks some of the 360's minor DLC (although the DLC doesn't come with the 5th anniversary edition for the 360), but the PS3 version is the technically superior version. My recommendation to you is to go with the PS3 version as a few small DLC and the lack of one extra bug aren't worth the price of technical inferiority... especially for such a large game.
http://ps3.ign.com/articles/762/762108p1.html