To distract the Wiki from the chat/forum kerfuffle going on recently, I decided to post this blog regarding my recommended mods for Skyrim, to follow up the one I made a few months ago for Oblivion.
Obviously, these are only for PC, and I'm using Steam, though they all run on non-Steam version as well. The Skyrim Script Extender (SKSE) and Skyrim UI (SkyUi) are required for most of these to work, except the Unofficial Patches.
1) Unofficial Patches (Main Game, Dawnguard and Dragonborn)
A must have, even if you dislike modding the game. All these do is fix countless bugs Bethesda hasn't fixed as of the latest patch, which will never be fixed by Bethesda as they've stopped working on it.
2) Sleeved Legionnaires+Sleeved Hold Guards/Stormcloaks
Ever get annoyed how even though Skyrim is a northern province, most soldiers and guards are walking around without pants or sleeves? Well be annoyed no more. All Imperial Legion armors and Stormcloak armors will have sleeves and pants, while Hold Guard armors for Winterhold, Dawnstar and Windhelm will all have them as well, while the Solitude, Morthal, Markarth, Riften and Falkreath armors have half the guards with sleeves, half without.
3) Water And Terrain Enhancement Redux
A simple yet beautiful mod that changes all water in the game, making it look much more realistic than in the vanilla game.
4) Qaxes' Winterhold Rebuilt
A simple mod that rebuilds all the ruined buildings in Winterhold, mostly new businesses. The quest is fully voice-acted by reasonably good actors.
5) LeanWolf's Better-Shaped Weapons
Many of Skyrim's swords were oddly shaped, like paddles, unlike Morrowind and Oblivion which had much better looking swords. This mod reshapes all the swords so they're sharper, thinner, and more like the previous games. A nice touch even makes it so that the loading screen ones are changed too!
6) Open Faced Helmets
This mod changes Hold Guard, Stormcloak, Steel Plate, Ebony, and Daedric helmets so that they open helmets. Now you can see the guards' faces as they spout their lines at you!
7) Dual Sheath Redux/XP32 Maximum Skeleton/Immersive Animations
These three mods go together quite well and add a few things: shieds and staves for both the player and the NPCs will now be on their backs, with options to put single one-handed and dual one-handed weapons on the back as well. It even adds a drawing animation in third person from your back, but sadly in first person you still draw from the hip (it bugs me a little). Running, sneaking and straffing animations are tweaked to be more realistic.
8) Run for you lives!
This mod makes all villagers and non-essential NPCs run inside the nearest building when a dragon attacks. Guards, soldiers and essential NPCs will stay and fight.
9) Immersive Patrols
For a province full of warring factions, Skyrims roads were mostly devoid of troops. This mod adds regular 4-5 man patrols for Imperials, Stormcloaks, Dawnguard, Vampires, Forsworn, and Bandits. This can be tweaked so they'll only attack you if provoked, or attack you immediately depending on your chosen side.
10) Civil War Overhaul
This mod used to be buggy as hell, but recently it's been patched so 9/10 of the previous bugs are fixed.
This is my personal favorite. Quite a bit of content for the Civil War was de-activated by Bethesda for the final release of Skyrim, and this mod re-activates the in-game files and adds some more. It adds quite a bit, including Breton and Redguard Legionnaires, trained Giants and wolves for the Stormcloaks, Imperial Champions for the Legion, and both sides get War Mages and more Archers. It also tweaks the AI so that ranged units will hang back and provide fire while melee unites charge in. You can also lose battles in this: you have a fix number of allied reinforcements, if they all die, you lose the battle and maybe the Hold. Lose too many, and your side will actually lose the Civil War.
Once you begin the Civil War questline, Holds can be attacked by the opposing side at any time (after the battle of Whiterun quest if I remember correctly), forcing you to go defend them or lose them. If you die in the battle, you wake up in a nearby allied camp. You must also assault each Hold capitol like at Whiterun to take the Hold, not just a single Fort. There are also unique rewards for each faction, Tullius/Ulfric won't just give you a leveled weapon anymore for each battle won. The two leaders will even join the battles from time to time.
11) Guard dialogue overhaul
Tired of guards asking if you "fetch the mead" when you've been the Harbinger for months? Annoyed of them never seeming to notice you're the Thane, except when you commit a crime? Well this mod overhauls the dialogue so that the guards won't seem like utter morons when talking to you. They'll even say "Hail, Thane" often.
12) Realistic Lighting Overhaul
This mod changes every light source in the game to make it, as the title says, realistic. This translates into: a lot darker in indoor locations! Torches are now actually usefull in 99% of all caves, dungeons and tombs, but this mod actually improves FPS due to the changes it makes to the lighting system. And it looks good, too. Win-win.
That's it for me, feel free to add any you recommend in the comments.