In my opinion there were too MANY bears, wolves, etc. chasing you constantly to the point of annoyance. Less hostile animals would be fantastic.
I remember a certain mod that added more realistic beast behavior (I think it was Oscuro's Oblivion Overhaul, but I'm not positive). Basically it made it so beasts would ignore you, run away, or attack depending on your proximity to them and how fast you approached them.