I wanted to mention a few mods that have been created or updated in the last months, for those people who own Morrowind and would like to give it another shot. If you don't have it, read a bit about it and then buy it!
Julan Ashlander Companion
This companion mod adds the ashlander Julan to the game, who will join you on the Morrowind Main Quest. You can ask about his opinion on the subject, has a few quests, and is a nice guy to have around!
Connary's Retextures
Several months ago, Connary showed up at the Morrowind Mod Forums and started releasing all kinds of texture replacers. While they are not as 'high-rez' as other texture replacers, they keep the original Morrowind feeling and look good as well!
He has retextured many things. Items, buildings, and many creatures. He even retextured the books from the LGNPC mods and some creatures from Piratelord's 'Creatures' mod. Which brings us to the following...
Piratelord's creatures
This mod adds a lot of new creatures to the game, and are mostly lore correct. The most recent version is 'Creatures 9'.
There isn't much to say, you'll have to look at the screenshots.
All I can say is that I've been using this ever since I first found it. Piratelord is currently working on 'Creatures 10'.
LGNPC Project
Less Generic NPC's is a mod that gives many npc's who don't have anything original to say new dialogue and quests.
Many LGNPC mods have been released already, but more are coming!
Morrrowind Graphics Extender&Morrowind Script Extender
Both utilities are still being worked on. MGE is most famous for the distant land feature it adds.
And MWSE is used for a lot of mods. Especially Fliggerty's. MGE is currently waiting for the MWSE update,
because MGE will integrate the new version of MWSE into the program.
Fliggerty's mods
Fliggerty's Morrowind Mods
Fliggerty's mods usually use MWSE (Morrowind Script Extender), and adds all sorts of interesting and useful things to the game.
And when they're not really useful, they're funny. Take the 'Mostly-Mini Todd' mod for example.
This mod adds a small companion to the game who has Todd Howard's head! Todd Howard actually made a post (He hasn't posted anything for a long time) in the release thread on the official forums. 'Best. Mod. Ever.'
Other mods worth checking out are Darknut's Armor Retextures, Tamriel Rebuilt (Yes it's alive!) and Morrowind Comes Alive. There are many more, which you'll have to discover yourself!