Maybe a sort of limping animation or visible wounds? Some proper death animations would be nice too.
Bring back that thing from Morrowind, where to advance a rank in a guild/faction you needed certain skills at such a level. Why is my knight character archmage? He can barely cast any spells!
NPCs need more variety. Different body models- hunched-over old people, big fat lords, skeletal beggars, y'know.
Also, give Skyrim some children!