0.
Loot and
Wrye Bash and/or Mod Organizer 2. These are mandatory mod utilities that will make adding mods to your game a relatively pain free experience. At minimum get Loot and Wrye Bash as MO2 is more for advanced users.
1. Arthmoor's
Unofficial Skyrim Special Edition Patch (USSEP) BECAUSE 6.8M PPL CAN'T BE WRONG. ABSOLUTELY MANDATORY. DON'T ARGUE WITH OR QUESTION ME. JUST DO IT. Must download this even if you download nothing else for the game.
Arthmoor fixed ALL of the game breaking bugs Bethesda couldn't be bothered to fix after game release since 2011. Minus the chronic, proprietary game engine ones that date back to as far as Morrowind. Three other mandatory mods from Arthmoor to enhance game play performance:
- Run for Your Lives/When Vamps Attack (merged mod forces NPCs to run and hide in safety of their homes/inns and indoors from Dragons and Vampires),
- Cutting Room Floor (does what it says on the tin aka restores cut content Bethesda left from game), and
- Alternate Start - Live Another Life. Really critical if you're the type of gamer who frequently rolls different character builds, want a change of scenery besides the fated vanilla hay ride, love a PC backstory, or simply don't want to keep entertaining yourself. Having to tolerate the appearance of that insufferable, egotistical flying Aedric lizard. And especially having to re-live watching poor Lokir get the Guinness Book record for being the first NPC to die in game.
2.
Chesko's Frostfall and Campfire and
SSE updates. Again MANDATORY. Skyrim is a cold, artic based province with four seasons and many various biomes. This amazing mod suite has a wide range of weather and climates. Which in turn, will obnoxiously prod you to remind your PC to dress appropriate. And plan ahead before they travel to the artic/tundra regions (Winterhold and Throat of the World etc).But all that aside, do install this. It's Chesko's last gift to the TES community before leaving the TES universe for better things.
3. Isoku's
Wet and Cold and the
Holidays mod. The former gives your PC a realistic body temperature response to the elements and environment. Going swimming in the Sea of Ghosts should've killed you within minutes from exposure of any skinny dipping. Now --with this mod working in concert with Chesko's Frostfall, it most definitely does.
The latter mod consists of festive NPC community events
based on TES lore holidays and festivals Which cause NPCs to gather in the town squares, inns and taverns to eat and drunkenly celebrate events. Holidays dedicated to game events like the end to the Civil War. And even the Dovhakin's birthday!
The Harvest's End holiday is my favorite, because the NPCs behave exactly as described here. My DB Dovahkin had a blast drunkenly chasing one of the village goats around the town with the kids.

In fact, just get any and all environmental and realism mods by Isoku (aka
Wonders of Weather, Realistic Water 2 etc). The guy's a freaking genius.
4. JohnnyWang13's
Cathedral Weathers and Seasons. What is says on the tin. And because Bethesda's vanilla weather & lighting system was a complete joke. If you install the Wet & Cold mod (with Frostfall & Campfire), now getting wet will increase your exposure to the elements. Which can and will result in your PC's untimely death if they don't find a way to dry off (build campfire, drink hot teas/warm stews, change your clothes etc etc). Also get
Minty's Lighting During Storms mod and
Supreme & Volumetric Fog which are companion mods as well.
5.
Hunterborn and
Real Wildlife Skyrim. Vanilla Skyrim should've been teeming with wildlife that you could hunt. Now you can chase that cheeky reindeer halfway across Skyrim with the proper hunting equipment. And then enjoy an immersive RDR style skinning animation once you catch it. Also get Fishing in Skyrim - because Nords, contrary to popular opinion, are not barbarians. At least where it comes to grabbing fish out streams and rivers with their bare hands.
6.
Northern Bathhouses and
Bathing in Skyrim mods. Because the Dovahkin DOES get filthy from his dungeon crawling and wilderness adventuring exploits every day.
7.
Realistic Needs and Diseases (RND). Gives your PC a stomach and appetite. And they can catch disease from food poisonings and other maladies like wound infections, hangover from drunkeness, sleep deprivation etc. Also adds immersive features like food spoilage and milking cows. Designed to work with Frostfall/Campfire, Hunterborn and 90% of the mods on this list due to a huge number of patches.
8. Vurt's
Skyrim Flora Overhaul. Makes Skyrim the Scandinavian alpine forest it should've been at launch. And makes all other biomes even better
9.
Mealtime - A Food and Recipe mod Had to link this one. With this amazing food mod, both vanilla and custom made food found in Skyrim is finally food they can enjoy. Thank the Nine! One of the Best food mods to date. Let's your PC cook, brew up and eat a ton of stews, soups, salads, roasted meats, dairy, bakery goods, alcohol/spirits etc. etc. with RND installed. Works perfectly with Frostfall Campfire.
10. At minimum, these amazing locations and/or quest mods:
- Beyond Skyrim Bruma Series: Because 410K+ Skyrim fan bois can't be wrong. Burma Opens southern Skryim border so you can play in northern Cyrodil
- Legendary Cities - TES Arena: adds back several immersive and legacy TES 1: Arena towns and villages with NPCs etc. all over the map
- Legacy of the Dragonborn Museum. A LEVIATHAN compilation of several popular quest and location mods (to include likes of Moonpath to Elysweyer etc). If you have Arthmoor's Live Another Life, then you can start the story as a Museum curator and adventurer. You'll begin the game at the Solitude Docks where you'll be met by a NPC who directs you to your new career at the Solitude Museum. If you have this mod, be sure to
- Solitude Expansion Mandatory overhaul and remake of Solitude exterior. What the capitol of Skyrim should've been at release on 11.11.11
- Lakeview (Hearthfire home) Expanded. AC3s version is here and AndreaA's Lakeview Manor As It Should Be. the AndreaA modder is probably a irl home interior designer. Because Oh my God.
But IMO AC3s is slightly the better of the two as it mods only the exterior. Leaving you free to pick whatever custom home mods you want for the interior. AC3s version also adds several immersive NPCs ranging from security detail consisting of NPC guards and mage, apothecary, smith, gardener, fishery & fisherman, a vampire jail warden (who likes to "host" criminal NPCs in her jail for "experimental studies", and several other staff who protect the premises from bandits, random rogue Aedric dragons, hostile critters, vamp Lords, DB cultists, and your 6 psychotic children (If you've installed TMPhoenix HF Adoption mod that let's you adopt up to 6 kids). And oh yeah, that annoying giant neighbor who lives in the Giant camp just due east. He likes to pop in for tea and crumpets once in a while. So he can off with your cattle. 