I don't know if someone else has brought this up before, but I would really love the addition of a homestead house or two that is earned via stealing/Thieves guild. Some kind of shady, den that's hidden away. Or possibly to work with the Assassin's guild to kill and take over someone's home.

What would be even more fantastic is having the chance for a stolen item to be a rare, uncommon or common version that can be actually used in your home. So many of the stolen items in game are interesting and it'd be cool to fill a den full of these spoils and curios.