I want to see NPCs that change based on your actions. Not a lot. but some.

Like... Winterhold. Sure, they arent ever gonna like mgaes. But if your character, a wizard primarily, came in and started doing allt these selfless acts just to help people you don't even know, I'd like to see at least some of the people there be a bit warmer to you, a bit more willing to admit that not all magic is bad.

After I've saved the world from a horrible destructive threat, I really don't like Balgruuf saying to me "Fancy Robes. you a wizard or something?" Its like, no Im the dragonborn. Remember, when we caught that dragon together?

Maybe some of te anti-dunmer people in Windhelm would come and not dislike so much if a dark elf came and helped. You'd still have that drunkard who stumbles around shouting slurs -- you cant win everyone. But just a general tone of acceptance that someting happened and that people are willing to look upon stuff a little better.

This wouldn't have any quest or lore implications; it would solely be in the 'feel' of the game. An acknowledgement that things have moved foreward. Even if its only appearance is in slightly altered NPC comments you hear when passing by.