Skyrim enthusiasts launched a massive mod that completely overhauls games' cities. The Holds: The City Overhaul mod weighs in 4GB in size and has been in the making for three and a half years, it makes the various cities and towns in the game much bigger than before, with lots more people, buildings and personality. You can download the mod via NexusMods.
What to expect
Memorable cities and new settlements, named individual characters with daily routines and background stories. New shops and inn's, new designs and new books, new outfits, and new locations and secrets to explore and more content in the future, as well as focusing on the other weaknesses that Skyrim has compared to the other games.