I'm late to the commenting party, but I agree with you almost wholeheartedly re: Fallout by Bethesda. Indeed, Oblivion is not quite as high on my list of greats as yours (I tend to prefer more linear RPGs), but I am convinced that Fallout 3 can and will be as fine an example of its craft.

But I do have my own concerns. Everything I've seen of the mechanics works out. VATS is awesome, Bloody Mess is glorious, and the Capital Wasteland is as "wasteland-y" as anything that ever was. But again, t