I for one would like to see what you would define as a good looking shack.
HAha!
The texture work in this game is simply phenomenal. Look at any modder and they are going to have a tough time beating it, even at 2 and 4 times the resolution. Not to everyone's taste though. Not really a fantasy setting, more of a real hard life setting.
The town design is great, although as anyone who has been anywhere, looking for a house to buy, you will notice that most of the towns are very small, a bit worn out looking.
I do find Riften extremely drab, the good design is hidden underneath grey-browns. Now the framerate improvement of 1.4 patch has revealed a nicer experience and I'm warming up to it.
I am currently testing this Vivid Riften mod:
http://skyrim.nexusmods.com/downloads/file.php?id=7001
I basically just decided to drop the texture folder in there and see how much I dislike it, but to my surprise, it's actually quite nice. I'm not finding anything bad, really. Performance is just fine as well. Give it a try. It's not as exaggerated as it might look in the images (like the yellow walls in the image, I never noticed that in-game). It's just that's how drab Riften was.