1) Skyland (Architecture AiO, Landscapes AiO and Dawnguard), Rally’s Solstheim AiO and Ruin’s Clutter Improved gives you p complete coverage. personally, I wouldn’t do more than SMIM Essentials but ymmv

2) ELFX + ELFX Fixes or the Lux suite, depending on space & if you want exterior lighting type too. both are superb for interior graphical fidelity, imo.

3) Variations and/or a 2k aMidianBorn for V+ or The Armory Extended for not V+. this is one you may need to play around w more than others to see how they look to you. this one area that the whole 1k/512 or straight up 512 does not work for me personally at all; but again ymmv

4) The Skyfall Tree Mashup looks amazing and has been performance friendly for me.

5) Real Humans and Beasts, if you have space, or Skyrim of Tamriel - The People UNPB

I know you didn’t ask, other than mentioning lighting, but weather makes a huge difference for graphical fidelity. imo the best are still Rustic, Obsidian and Cathedral. I love so many more weathers than that and I use way too many to list, but for A Graphical Masterpiece, it’s one of those 3, for sure, (imo) as they seem to enhance your great textures somehow