Definitely Skyrim, but I probably won't be playing it straight away. I'll likely still be playing Dark Souls. Regardless, as far as November releases are concerned, Skyrim definitely has my interest more than any other.
Also, the new Assassin's Creed game that is coming out is not Assassin's Creed 3. It is called Assassin's Creed Revelations. Not trying to be uptight about this, but Brotherhood wasn't 3 and therefore neither is Revelations. They are clearly saving the trilogy number for when a new character becomes the primary focus.