The fantastically beautiful world of Oblivion has really a lot to offer: wonderful landscapes with always different accents (depending on where you are - and what time of day)! A great staged main quest! Lots and lots of side quests! A very clear control and management of objects and quests! A selectable perspective (and RPGs with selectable Egoperspektive for the PS3 are truly a gem)!
Even after months or even years of roaming the world is you still find something somewhere, that's a far escaped. And since even looted Dungeons fill up again, you can, because if one emphasis on collecting, theoretically looking for all eternity for artifacts sunken cultures.
What I also like very much: In contrast to the present apparently usual gloomy ending Mood scenarios (Fallout, Borderland, Metro, partly Dragon Age ...) we must at TES 4 at least away from the hell-like Oblivionebenen sometimes indulge his eye: with romantic country strokes , beautiful trees, colorful plants, harmless deer, birds and butterflies, brightness, sun, green ... all accompanied by a soundscape that really sucks into one of the action. By boiler-like shape of the map you have down on the raised edge areas of truly breathtaking views of the world.
Although now a few years old, Oblivion still has a beautiful graphics, even if one would model detailed figures today. And I have no other PS3 game I still regularly get after such a long time out of the closet to make me a cozy wine evening on the couch.
Hopefully TES is 5 also such a marvel (and hopefully they do not emphasize the first-person view, as it seems at present to be so common).