I voted for everything except graphics and skybox. While OB does look nice, other games look nicer, without the huge hit to performance that Oblivion has.
It's a very good game, but I wouldn't say its the best. GTA IV is still my favourite game ever and, at least in my opinion, Fallout 3 and New Vegas does everything in this poll slightly better except maybe the diversity in the map. Coming out of the Fallout's and into Oblivion all of the varying locations is what impressed me the most. I realize that this can be a volatile thing to say in the Oblivion forum, but I'm a Vault boy at heart.
I am an FO fan. FO3 does indeed do most things better than OB. That is because Bethesda took what they learned in Oblivion and applied it to FO3, especially with the graphics and game engine. But also with improvements to character leveling, enemy and loot scaling, etc.... OTOH, I find the dull brown expanse of the Wasteland gets monotonous after a while, and always find myself yearning for the green fields of Cyrodiil once more. Likewise, I like how Oblivion gives us a diverse set of races to play, each with their own unique appearances and abilities, where in FO3 you can just pick from human, human, human, or if you don't like those three: human. That, and the presence of things like birthsigns, spells, etc... creates much more replayability in Oblivion for me.