@comfy
I have added a mod adjusting difficulty to be irrelevant to your level: (dragons are deadly, don't try approaching Daedra, go kill rats), as well as return an xp based skill system.
And the game transforms completely. I had no idea just how much detail there is already in the game. The world is much deeper, then the main quest implies.
But for me the definitive mod was that one mod that just changed all of the perks so it was actually viable to do actual character builds instead of stealth arching despite being a clear mage or warrior type