Seriously, of all the things the multiple demos showed off at E3 it was the facial animations that surprised me the most. Not only on Connor's face but on the NPCs too. There is a particular scene where Connor is talking to someone in a camp during the Ubisoft demo that impressed me. Now it's not LA Noire facial animation but it's pretty good for something running on a PS3.
What impressed you the most? Is your excitement greater or lesser after E3? Personally I can't wait for October 30th.