[QUOTE=The Great Hairy]I think I found the Ultimate Mod List (tm). Go here:
http://www.mwmythicmods.com/telesphoros.htm
All of the mods Dragon Wench listed are there, with direct links. I'm downloading several right now.
[/QUOTE]
Yes, Telesphoros' list is the best maintained, and the most accurate. Most mods are available through central locations (like TES, TheLys, and Morrowind Summit) but there are some whose authors prefer to keep 'em on their own personal sites, alone. Telesphoros often lists these.
A few of my own favorite mods:
Super Adventurers 3.02. Adds plenty of tweaks to the game, generally making it somewhat harder (but in a few cases, easier). It's meant to rebalance things more sensibly.
Dracandos' Voice. When you get to the top of a guild or faction, this mod gives you some neat new abilities. For example, you can send any member of House Telvanni on a mission as Archmagister, while you can practice combat with any Imperial Legion soldier or guard as Knight of the Imperial Dragon.
Fair Magicka Regeneration. Four scripts; you choose one to set the speed at which magicka regens. Note, it affects your opponents as well as you.

The nice thing is that you don't have to guzzle endless potions or sleep to regain magicka.
Sri's Alchemy. Adds new alchemical substances, and removes Fortify Intelligence (which is really cheesy) from the game.
Haldenshore. So many mods are located in or near Seyda Neen that crashes and conflicts are common. My preferred mod for that area is this new town to the south, which adds a thieves guild that you help establish. There are 16 thieves' quests, and a nice idea: you get a cut of the guild profits. So the more quests you accomplish, the more you benefit the guild, and the more money you acquire on a regular basis. Also includes a loanshark, betting on fist fights, and an underground bar.
Potted Plants 2.0. Many plants to choose from. You get a customized pot, and the plant produces an herbal ingredient in 11 days, and every 30 days, after that. Available for purchase from Ancola's stall in Sadrith Mora.
Real Furniture. Creates a merchant in Vivec that sells 400+ pieces of furniture and housing decoration, with many different styles. Objects can be turned, lowered or raised once put in place thanks to a special (very cheap) ring you get at the store. Once the object is set as you'd like it, take off the ring.
Disturb the Dead. Adds decent loot to tombs, but at a cost: the dead are aware of your pillaging. You'll be attacked frequently, and cursed, lowering your attributes until you purchase special potions at a temple.
Pack Animal Merchant. By Baratheon79, one of the best coders for this kind of thing. It adds a merchant on the outskirts of Pelagiad who will sell you pack rats and guars.
Lights 300, v. 4.1. By Byblos. Gives every candle light the same color as the candle wax; so red candles produce a red light, etc. You might need to tweak your ini settings to take advantage of this one, but it really creates some nice effects.
Modtown 2004. Take a bunch of modders of known quality. Put 'em altogether, and let 'em create a small town with personal residences simply designed to show off their skills. The results are extremely inventive in a just-for-fun mod, where you wander about trying to find every secret little detail that they've each added.
Psorticon. Gives each type of scroll and potion you acquire it's own color and symbol, making it far easier to identify at a glance.
The Imperial Legion Badge. Tired of having to put on all that armor you receive as a reward every time you go to an Imperial Legion officer for a new quest? This badge gives you instant recognition without all the useless metal.
Morrowind Advanced. Makes the game more challenging: a few new dungeons, with new weapons, armor, alchemical ingredients, and more difficult creatures. Feel like taking on a Rogue Ash Ghoul, a Red Warrior Dragon, or an Elite Dremora General? It's all done with leveled lists, so you won't get stomped on by a Winged Twilight Hunter while level 3.
Havish. By the same modder as Haldenshore. This is a major city, on a landmass west of Vvardenfell. Once again, a new thieves guild with 20 quests, but also 8 quests for a fighters' guild, and 8 for a mages' guild. Has a banking system, and gambling--you can play blackjack, and bet on rat fights.
Dwemer Bio-Monitor. This is an ease-of-use mod. You put it in your inventory, and it monitors your health. At defaullt settings, if it finds you below 30% of health, it will automatically administer any health potion you carry. This also applies to fatigue. You can change those settings.
Morrowind Wallpapers and Loading Screens. 66 splash screens (the kind that show while Morrowind's loading) that make the stuff that came with the original program look like the efforts of a 5-year-old. Beautiful images by day and night of many areas, shrines, and cities--with more on the way. Nice font, too. You'll need an image program like IrfanView (free, by the way) to resave the each of the files as 1024 x 1024 and in targa format, but I did that in less than 15 minutes.
Magistrate's Mage Guild Rewards 2.0. There are already a few mods that provide reward incentives to reaching the top of a guild or house--Dracandros' Voice being probably the best--but this one is more detailed. It adds a teleport room that lets you move quickly to any of the Mage Guilds for free, and a second-in-command who buys and sells magical supplies, enchants, offers a few spells, and even repairs items.
Abu's Retreat. My favorite house mod: lots of plants, lights, books and wall hangings really make this one seem lived in, rather than simply a warehouse. Has a nice alchemy lab (all ingredient jars, including Sri's), a very attractive kitchen area, a decent display room, and a small but great greenhouse that simulates the effect of daylight or night through the glass roof.
Enchanted Icon Selection. One of those tiny ease-of-use mods I love. This one gets rid of the horrible enchantment icons that cover whatever you're looking at, and replace 'em with a selection of very easy to see symbols that only affect a small portion of the icon surface.
Journal Enhanced. Move a quill across yourself in the inventory screen, and it brings up a box that lets you add journal entries. You can't affect anything written in the journal by the game, but it's a nice add-on.
Writing Enhanced. Buy a special book or scroll, move it across yourself in the inventory screen, and you can actually create a new book/scroll in the game, complete with title. You can go back at anytime and pick up where you left off, and re-write the entire thing, and you can export copy to a textfile.
Dodge. If you're playing a pure mage, get this. It adds a dodge bonus based on your unarmored skill, effectively making unarmored a reasonable choice instead of a deathwish.
Sorefoot Enterprizes. The Silt Strider business is expanding, with new locations, buildings, NPCs, and quests. Good writing, some truly creative questing, as well.
Herbalism Lite. Another ease-of-use mod. Instead of having to open every plant you come accross and extract its contents, this mod makes the process automatic. Click on the plant, and its contents are moved to your inventory. If nothing's in the plant, you'll be told so.