Haha, people actually consider the huge lifeless 'random' world of Oblivion better than the more focussed non-linear setup of the world in Stalker?

Oblivion has 'the' dumbest use of vast terrain ever. Hell, the game didn't need it at all but included it anyway (what they needed was a better AI and gameplay). They could have gone for more FarCry like setup for the world which was more focussed and didn't involve you bashing your head against the wall after encountering another random dungeon with unintresting loot. Hell, even the houses didn't have any interesting loot.

You can't compare Oblivion, a poor excuse of an RPG with Stalker at all. Stalker gives you variation, sometimes subtle, sometimes huge. This in-fact has to be the first game ever which uses the vast terrain properly where every house/warehouse or city has a purpose, if not for gameplay then for the ambience.

No wonder FarCry 2 is trying to copy this same thing, even though it takes place in a generic world, but the design is still more focussed than anything Oblivion.