really The biggest think to me that would make the game better is an expansion that let you rebuild winterhold and maybe even becoming its Jarl(maybe?) I mean it always bother me that winterhold which is called a city is smaller than town in the game, has no walls and maybe 3 building besides the mages college. and I feel like with some of the things that they are adding in hearth fire could be used in the rebuilding of winterhold.
as for some of the gamejam stuff
seasonal foilage
Chose Followers favorites
a few others I cant think of
and of course eventually an expansion like Shivering Isles.