Part 3 - Graphical Mods

Miscellaneous

Mesh Improvements Optimized by Stuporstar

Contains a variety of smoothed and optimised meshes.
Better Meshes plus Optimization by Tarius

Contains a variety of smoothed and optimised meshes.
Correct Meshes by ZWolol

Fixes a number of mesh issues.
RR Mod Series - Better Meshes by Resdayn Revival Team

Contains smoothed meshes for various objects.

Includes optional half-size potions.
Mesh Fix by Slartibartfast

Contains 121 fixed and improved meshes.

Includes some improved meshes from Better Meshes and Mesh Improvements.
PeterBitt's Small Mods by PeterBitt

A collection of small mods which includes several graphical mods.

Collision Fix, Fireshield Icon Fix and Grahl Eye Fix are all straight-up graphical fixes. Scroll and Potion Icons is a bit more down to personal taste, but makes scrolls and potions a lot easier to differentiate.
Misc Items Replacer by Qarl

Replacer for many of the miscellaneous items in Morrowind.
Bottle Replacer by Qarl

Replacer for the 15 varieties of bottle in Morrowind.
Smoothened Mesh Req's by Ashiraniir

Contains smoothed meshes for various objects.
AOF Containers by AnOldFriend

New barrels, kegstand, wooden bucket, and optional new sack textures.
Better Kegstands by Tarius

Improved / fixed kegstand meshes, along with an improved texture.
True Gold - Gold Coin Retexture by FrostByte

Texture replacer for gold coins.

There are lots of other gold coin replacers out there but this is my favourite of the ones I have seen. Note that it does not change the icon.
Better Picks'n'Probes by £exa & HG-12 & Sister

Texture replacer for lockpicks and probes, along with improved / fixed meshes.
Dwemer Puzzle Box and Key to Lower Arkngthand Replacer by Pikachuno

Mesh and texture replacer for the Dwemer Puzzle Box and Key to Lower Arkngthand.
Bloodmoon Hide Replacer (BHR) by Alaisiagae

Replaces the Bear, Snow Bear, Wolf, and Snow Wolf Pelt ingredients so that they actually look like pelts.
Cart Cloth Retexture (CCR) by Alaisiagae

Vanilla-friendly texture replacer for the cart cloth found in Tribunal.
Daedric Key Replacer by Alaisiagae

Gives the glowing daedric key a new model and icon.
Flask Replacer by Qarl

Replaces the 4 flasks in Morrowind with better meshes and textures.
EKM Vanilla-Based Paper Lanterns by Erikaimar

Vanilla-friendly texture replacer for paper lanterns.
Dunmer Lanterns Replacer by Melchior Dahrk

Replaces all Dunmer lanterns with smoother, more detailed versions.
Silverware Enhancer by GhostNull

Replaces all silverware items with reflective, higher-poly versions.
Papill6n Various Graphics Things by Papill6n

This includes a LOT of very nice vanilla-friendly graphical improvements.

Install it after all the other replacers, as it will override a lot of files from other mods. It's broken down into optional components, but you probably want to install everything, except perhaps the "DarkUI new main menu", and of course only install one of the "Fabric on the imperial altar" replacers.

This includes modified versions of the various "Reloaded" landscape textures by LestatDeLioncourt, which are more vanilla-friendly than the originals.

This is also the definitive vanilla-friendly soul gem replacer, based on Earth Wyrm's Souly Soulgems(!), Infectious Moon & NelothsMouth's Soul Gem Replacer Retextured and Jericho, Lokichan & Lord Alex's Better Soul Gems.
Max's Glow by Max

Changes the enchanted item "plastic wrap" effect to look more like tiny flashes of electricity.

A notable alternative is Plangkye's Pluginless NoGlow, which removes the effect entirely.
Walther's Blood Sprite by Walther

A more realistic blood effect.
Flies by R-Zero

Adds a visual effect to all "flies" sound emitters.
Error Marker by Fliggerty & Friends

Makes the "error marker" for missing meshes a lot less intrusive.

Fingers crossed, you should never see any error markers, but just in case!

Part 3 - Graphical Mods

Miscellaneous

Mesh Improvements Optimized by Stuporstar

Better Meshes plus Optimization by Tarius

Correct Meshes by ZWolol

RR Mod Series - Better Meshes by Resdayn Revival Team

Mesh Fix by Slartibartfast

PeterBitt's Small Mods by PeterBitt

Misc Items Replacer by Qarl

Bottle Replacer by Qarl

Smoothened Mesh Req's by Ashiraniir

AOF Containers by AnOldFriend

Better Kegstands by Tarius

True Gold - Gold Coin Retexture by FrostByte

Better Picks'n'Probes by £exa & HG-12 & Sister

Dwemer Puzzle Box and Key to Lower Arkngthand Replacer by Pikachuno

Bloodmoon Hide Replacer (BHR) by Alaisiagae

Cart Cloth Retexture (CCR) by Alaisiagae

Daedric Key Replacer by Alaisiagae

Flask Replacer by Qarl

EKM Vanilla-Based Paper Lanterns by Erikaimar

Dunmer Lanterns Replacer by Melchior Dahrk

Silverware Enhancer by GhostNull

Papill6n Various Graphics Things by Papill6n

Max's Glow by Max

Walther's Blood Sprite by Walther

Flies by R-Zero

Error Marker by Fliggerty & Friends