I think the best part about Morrowind was the political and moral ambiguity. In Oblivion its rah rah save the Empire. I play Dunmer and Khajiit and I rp--so why would I want to save the emperor--am I a self-hating Khajiit or Dunmer? Do I like my white-skinned imperial overlords with their imposed gods (which by the way was another b.s. innovation--true religion--I was initially charmed by Morrowinds mix of interesting local faith (but false, if appealing gods) and dull humdrum imperial catholicism (with near-absent gods unless you really rise in their silly herb gathering, fortress-hiding hierarchy). Morrowind starts you up and running--of course you are the Prophesied one!--don't you believe Mr. Cassius, the imperial spymaster? Surely he has no ulterior motive for manipulating local beliefs into instilling an imperial puppet in place of a prophet! (showed him right when I slaughtered the last imperial in Morrowind with my Daedric Crescent). Try doing that in Oblivion.
Oh and as far as amazing Morrowind mods go: best there is (beats Oblivion's interactive npc anyday): Antares' Big Mod (
http://planetelderscrolls.gamespy.com/View.php?view=Mods.Detail&id=5892)
Features include:
Hirelings
1. mark targets for theft or assassination and hire a local to do it---true to canon enough that if you mark a Great House member, Morag Tong will refuse you, even under the table, but freelance assassins will still take you up (esp. great for second thieves' guild quest in Balmora when you have to pick pocket that guy with (at that point in the game) fairly-low sneak).
2. Employ the many scouts chilling around taverns to take you to local areas--tombs, caves etc--perfect short cut for tracking through wilderness at a reasonable price!
3. Employ the many agents to get you info, and help you join guilds including Morag Tong (the agent tells you to pick up the appropriate book and check Vivec's arena)--perfect for rprs who want to join the assassins, but feel weird just walking into the "secret" base.
Master rewards--available for every guild, but as a highlight---Temple patriarch can mark people as heretics and have them burnt at the stake (no joke), drop a scroll in an area to spawn a party of ordinators in 24 hours, and get almost any temple member to follow him/her.
there is other stuff too, but I love the Antares big mod more than I do most games