Like imagine if you took on a quest to save a womans daughter, you bring her back and after you're paid you attack them. What kind of reactions would you get? Say hypothetically you kill the daughter, what kind of AI behavior that would not impress me is the woman screaming and fleeing for her life, running to get nearest guards. Seeing her break down emotionally and through dialogue as well as facial expression express her grief, would be much more impressive.
Aye, harsh and cruel example that, but that's the kind of evil little bastard character I tend to play.
Point is, would be fun if you could push the game to the limits of social behavior and the game actually plays along rather than just have lazily programmed reactions to your actions. Offer to help someone chop wood for payment, he says okay. Pick up said wood and throw it in the water, and he would be angry and upset. How fun it would be to play a bully if the game acknowledged your actions!
Offer to take care of the customers of a store while the owner sneaks out laundring some money, and when they return they'll find that most of the valuables in the store are gone, and there you stand looking innocent. Yes, the smart thing would have been to make a run for it, but it's so much more fun to see what kind of response you'd get. Or spy on them when they return to see how they'd react, finding the store cleaned out.
What if you're on a hunting mission to hunt some deer and provide the meat for a family of farmers. Instead you go to the neighbour farmer, kill him, take his meat and under pretense that it is deer meat, give it to the family, then have the dialogue option of telling them who they're eating after dinner. Muahaha!
Remember that it has been talked about that your deeds throughout the world will bring you either fame or infamy. These kind of things would make for the most fun kind of infamy!
That's the type of possibilities I'd love to see in Skyrim. I know we're probably not going to get half of them but one can dream.