NoNewTaleToTell: Since we're talking Skyrim mods, this is an overview of what I have installed
Unofficial Skyrim Patch
Unofficial Dawnguard Patch
Unofficial Hearthfire Patch
Unofficial Dragonborn Patch
Unofficial High Resolution Patch
Falskaar
Wyrmstooth
Moonpath
TravelersOfSkyrim
Dark Dungeons for ENB
Immersive Battles
Immersive Brigands
Immersive Dawnguard
Immersive Dragonborn
Immersive Mercenaries
Immersive Patrols
Immersive Travlers
Immersive Werewolves
Imaginator
Winter Is Coming Cloaks
Hothrooper44 ArmorComplitation
Immersive Weapons
LeftHandRings
LeftHandRings - Dawnguard
Inconsequential NPCs
Run For Your Lives
When Vampires Attack
Vampire Overhaul
Apocalypse - The Spell Package
3DNPC (Interesting NPCs)
AmazingFollowerTweaks
Alternate Start - Live Another Life
Realistic Ragdoll Force
CLT (Craftable Lockpicks & Tools)
Craftable Low level Bows
Bandolier - Bags and Pouches
Train 99 Skills Per Level
Whistle
As you can tell I basically populated the world as much as possible, as I felt vanilla Skyrim was EXTREMELY empty. I also made crafting a bit more useful by being able to create lower tier bows, lockpicks (finally a use for those Iron Ingots!) and stuff of that nature, being able to call for your horse and being able to train until your gold runs out. Falskaar is a DLC-esque mod, both in size and scope, and it's actually pretty darn good besides a couple glitchy segments. Wyrmstooth and Moonpath to Elsewyr are supposed be like Falskaar but I haven't tried them yet.
The one mod that I consider a "must have" is Interesting NPCs. It adds over a hundred unique fully voiced NPCs, many of whom offer quests and some who are part of entire intertwined questlines (that are better than 99% of vanilla's quests) that can last for hours. Most of them are far more interesting (heh) than vanilla's, and the voice acting is generally solid too, though there are some characters with lower end voice acting.
I do occasionally use Frostfall but it typically ends up being more annoying than fun and gets uninstalled. It's best when playing with a new character, once you start questing all over Skyrim the mod just makes everything tedious, unless you're really into e-larping I guess.
I haven't had a crash yet with that current load order and it runs as smoothly as vanilla does on my laptop.
Yeah Skyrim without mods is very empty. Did all those mods make Skyrim give you less performance though? I'm guessing the more populated the world is, the more powerful your CPU and GPU need to be for smooth gameplay.