Morrowind Rebirth mod has recently got a big update to version 4.0, featuring expanded and improved areas, new creatures, spells, textures, balance tweaks, bug fixes fixes, etc. This is the largest patch to this mod that has been released so far. The list of changes is really long (you can find in in full length on ModDB), so lets just mention a few interesting adjustements. One of them is the new appearance of Dark Brotherhood assassins, who now look different depending on their rank. You should also be more careful when dealing with bounty hunters, especially if you have a bounty on your head of 500 or more, as they will approach you in different areas, mainly taverns.
Morrowind Rebirth is a complete overhaul for the classic RPG from Bethesda Softworks The Elder Scrolls III: Morrowind. With it, the original adventure becomes more difficult, but also more interesting. Cities have gained a lot of life and a bunch of new details, such as NPCs, houses, and shops. There is also a ton of other content, such as new enemies, weapons and armor, music, reworked landscapes and more. You can download the mod from this website.