Originally Posted by r3dshift
I don't necessarily need new features . I'd prefer a new storyline once I've beaten the game, complete with new dialogues/quests/whatnot, which can only be provided by an (official) expansion. IMHO.

New storylines too naturally. Hers som examples of content mods for morrowind:

Leaves of Lorien 1.2
- This mod adds a sleepy little island (Isle of Elenna) off the coast, directly south of Ebonheart docks. A bridge connects the mainland to the island. Pay heed to the "Welcome" pylons, for they hold the dreams of the Elves. The Island has been abandoned. The traces of a race of elves remain scattered across the island. The weeping trees bear gifts to aid you in your journeys. A full set of armour is waiting for you, and a challenge to seek out and claim the the armours of the High-elves and Dwarves who have long since left the Isle of Vardenfell [7 total, gender specific]. The mod also adds a playable race, the Valmer or Grey Elves. Alternate Link

Korobal Island v1.2
- 45 quests, a new landmass, and 344 new NPCs. Takes a build as you go approach.

Muffinwind
- Over 150 new NPCs, 100 new locations, and 20 hours of gameplay. It all amounts to some serious fun!

Oluhan 1.13 Final
- Adds a new faction, 40 quests, a secret underground city, and over 140 NPCs. Best of all you can hit the ground running at Level 1 with this mod.

The Black Mill
- Very long quest and new landmass. For level 25 and up.