The mods that follow are mods that only have 1 to 3 endorsements at the time of publishing this article, that in my opinion deserve a lot more attention.
Tetra The Pack Guar by Tizzo
Tetra is cute, Tetra is useful and balanced. She's also hassle-free. She (together with Paxon) is the finest beast companion you will ever find without MWSE requirements. Seriously.
Physical Wellness by Stripes
Admittedly not a mod for everyone as it adds difficulty to the game. The idea is simple but quite realistic: if the player is in a weaker state, they are more likely to catch a disease. Conversely, a healthy player is more likely to shrug off common diseases.
The Sunken Tower by Pianobadger
Explore the tower, it's sunken. It may not sound like much but it is a fun exploration. This mod was built with care and attention to detail. The loot is interesting but balanced. Very low chance of incompatibility: not even an issue with Morrowind Rebirth!
A simple items mods, perfectly executed: new enchanted items have been added to the levelled lists. They use, for the most part, vanilla enchantments, they are well-priced, and appear in reasonable quantities. The new items are mostly clothing items, a nice change since Bethesda only added rings and amulets, with the occasional robe (not counting unique items).