I tell you realistic lighting(the dark one that advertises darknights and a package of lighting effects) a new night sky/moons, torches for all actors, drop lit torches, and possibly a small smeak overhaul. this will change the look of skyrim, making everything darker and nights/dungeons a little more suapenseful. torches and/or magelight also becomes essential. The sneak overhaul is supposed to help npcs not see through the shadows.
then try a realistic combat mod. I'm pretty happy with the ACE package. . . although I use others in conjunction...
A mod to tighten your wallet will make you plan your purchauses better, and a true bargain hunter should make all homemade potions equal zero value. I take up the less profitable enchanting, but a miner makes an alright living.
I didn't really like skyrim civil war mods, I thought they went overboard and ruined the feel some, but others swear by them. Same to deadly dragons. I keep it so I can buff dragons and get an occasional 'intresting' fight.
other than that I found archrey op, so I tinkered that. magic also got a rework to make it interesting (and because every other dynamic of combat was modded by then).
maybe a suvival pack to add hunger/sleep/hypothermia/camping.