I was always fond of Voyage of the Dawn Treader.Also maybe Narnia? Like ignore most of the religious allegory, and the entire final book, and it’s a really fascinating world.
I’d love to see a D&D port of Thedas (Dargon Age), any good Hyrule based TTRPG setting…
Castlevania
Shades of Magic could be interesting.
The world of Doctor Norrel (so?)
Assassin’s Creed (maybe)

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.