Bear with me and indulge me for a moment if you will, I'd like to complain about an important aspect in The Elder Scrolls V: Skyrim: it's economy.
Get Rich Quick
This may seem like a minor trifle, but one thing that bothers me about Skyrim (other than a few other things) is how easy it is to accumulate a large amount of wealth. I ran into similar problems with games such as Red Dead Redemption, Grand Theft Auto IV, and Fallout 3. Whereas some games run out of ways for me to make money, games such as these and Skyrim run out of things to spend my money on.
Getting rich and being king of the world is a big part of an open world RPG. However, the fun part of an RPG isn't being the best, it's about being better. An RPG is more about self-improvement than competition. The saddest part of a role-playing game is hitting the level-cap, because you can't get any better. Sure, you're an unstoppable badass, and that is an important part of an RPG, but if there isn't something to rise and challenge you, it gets boring.
The economic system of an RPG works the same way. We should always have more money than before, but at the same time, there should always be more new and exciting things to buy. More supplies (useful supplies, not a 10% increase in magic resistance), more prestigious houses, upgrades, better, more powerful weapons, and more expensive items. Now, to some degree, Hearthfire did do this, and I would have liked to see more of that. It's OK to do a little scaling here. I don't want to sit on a giant horde of wealth, I want my adventuring to feel significant! If I go spelunking and find a whole bunch of loot, my entire experience is somewhat cheapened when those gold coins can't buy much. And speaking of loot....
For the Love of Loot
This might be a minor gripe, but it would improve the game a lot for me. I can add my items to a "favourites" category with just the click of a button, so why can't I do the same for items I don't want? I love looting, but I don't love hoarding. I don't want to sort through my inventory at the shop every time, so make it simpler! Take a look at Borderlands 2 and Dragon Age: Origins. Both of those games have a "Junk" option. You can go through you inventory and, with one button press, label your items as junk to be sold. This way, all of your unwanted clutter and valuable loot alike can be offloaded easily the next time you visit a general store. That also means less time talking to Belethor, which is always a good thing.