[Luis_A51]

1) Oblivion (Standard PS3 release) is Oblivion + Knights of the Nine expansion pack

2) Oblivion "Game of the year" edition also included the Shimmering Isles Expansion

3) The standalone Shimmering Isles is for people who bought 1) and dont wish to buy 2)

SO if you havent purchased any copy of oblivion yet, then the obvious choice is to get game of the year edition. Oh and Oblivion is an amazing game, I have the original PS3 release, and plan on getting Shimmering Isles (although my GF will kill me, she was so sick of me playing Oblivion by the end)