To add to this... Unarmed, Mysticism, Athletics, Acrobatics, Classes, Attributes, Greaves, Pauldrons...Oh my, I was only supposed to pick one? In that case, hiring competent writers would be my first choice. Second would be quest Skyrim's design cannot be repeated, it's just horribly implemented.
Oh damn, I did it again. I just can't choose one lesson that needs to be learned, there's too many missteps that have been made for me to choose that one thing that will make it better.