Fallout 3 or leveling in Wrath of the Lich King. OMG, this is a hard choice. I mean, with the Oblivion engine, I know the cheat codes, after all. Fight too hard? That's what TGM is for. Can't jump high enough? TCL. Mobs too skilled for you? Diddle with your stats. And I have never been disapointed by a BethSoft story.
So. Hard.
Steam might be an issue though (it does use Steam, right? I am pretty sure I read that) as it's given me trouble before, AND I have a whole new layer of complexity with the 'new' install of Windows, without wiping the old. (How? Um.. ask my Dad. I just know all the programs are still there, but I can't get some to work in the 'new' install, as they have associations with the old. I wonder just how much trouble it really is to un-install Steam....)