Caves of Qud is one of my favorite traditional roguelikes I've gotten my hands on. It's the closest I've ever come to feeling like I'm playing a videogame and reading a book at the same time. Originally, the worldbuilding pulled me in, but I found myself just lost in the intricate, poetic descriptions for every single item in the game. It makes it a delight to find a new thing you've never seen before. Even the dirt and trees have their own flowery, beautiful descriptions.
There's a range of options to tailor your experience, whether you'd prefer to play it like a roguelike or a traditional RPG - and the main quest line has a lot of goodies to show you but isn't really obtrusive at all.
The mutations and cybernetics systems are just more upgrade trees, but the design and the descriptions really make them stand out as something special for me. Everything just locks together into a really solid narrative experience, with its own funny and strange moments, that's also just plain fun.
Also, the devs are really active in the community and the public discord is one of the friendliest and safest places I've been online. I've learned a whole lot game from people there, and there's plenty of art and community involvement. Definitely made this game better.