Man, I see a lot of people jumping straight to recommending LitRPGs when dungeon dives come up, but I think that’s missing a whole layer. A truly great dungeon crawl novel isn't just about stats and loot—it's about the atmosphere, the sense of ancient, unknowable malice waiting in the dark. For pure, claustrophobic fantasy adventure, you can't beat older stuff like Steven Brust's 'Issola' or even parts of Glen Cook's 'Black Company' where they're navigating cursed fortresses. The tension comes from character choices and dwindling resources, not notification boxes. I re-read Lawrence Watt-Evans' 'The Misenchanted Sword' recently, and the sequence where the hero is trying to escape a wizard's labyrinth purely on wits and a single dubious magic item... that’s the good stuff. Modern progression fantasy often feels too clean, too gamified for my taste.
That said, if someone absolutely needs that LitRPG hit, 'Dungeon Crawler Carl' is the obvious king right now. The audiobook is a blast. But for the fantasy purist who wants the adventure without the system, the classics have a grit and wonder that’s harder to find these days.