So one thing that I miss from Oblivion is faction ranks in Skyrim. I know most of the factions don't seem to have any real ranking system in general. But having a ranking system that improves like fraction armor, perks, or just general interactions with the faction would add a bunch the the rpg element of Skyrim.
disclaimer: I do know that you get better faction armor, weapons and other things for doing more fraction story quests but they just don't have that oh look i'm ranked really high or i'm the grunt of the group.