I just got to level 45 (?) and although I've completed the main quest and I think several other large(r) quests my Miscellaneous list still goes almost from the top of the screen to the bottom, I only have two of those magic masks, the head of the Thieves Guild has been waiting for me to come back after his first assignment for something like 30 levels now, the only Assassin's Guild people I've seen are the ones I've buried after they tried to execute contracts, I haven't even talked to anyone about this war that's going on, still haven't seen a werewolf nor any of the Companions since level 1, etc. And stones? What stones?
I'm actually facing the possibility of playing this game forever doing random quests because I don't have a strategy guide, don't know about most of the quests you guys are always talking about and am still too busy and having too much fun to care. I think at this point that the only thing that will supplant Skyrim as my goto for gaming will be the release of Mass Effect 3, and then the release of Bioshock Ultimate.
Following that, it would take TES 6 to close the book on TES 5 for good. Similar to how TES 5 closed the book on Oblivion, Oblivion on Morrowind, etc. So I guess I'm done when I uninstall Steam?