One thing that really irritates me is getting caught pickpocketing, and having that person not only take back what I stole, but everything else I'm carrying that was stolen as well. I had almost half my inventory taken away for that once.
So, what I'm proposing is an NPC that, for a fee, "launders" your stolen goods for you, making them so they no longer register as "stolen", don't get confiscated, and are easier to sell. It'd be a godsend for the less-than-saintly players among us.