ADOM had a fancy re-release on Steam recently! It just showed up in my Steam queue.

Check out Dungeon Crawl Stone Soup. Feels like a much more modern Nethack, with convenience features (`o` autoexplore, `tab` autofight, etc.) and less of a focus on one-and-done intrinsic immunities in favor of tradeoffs ("this armor comes with cold resistance but vulnerability to fire").

For more of an "explore the world" feeling, Caves of Qud is on Steam and has a ton of depth.

Dwarf Fortress has Adventurer mode, which, although less developed than the more famous Fortress mode, is still really deep, under slow but active development, and has the unique value prop that you can build a fortress, leave it on autopilot, create an adventurer, go visit the same fortress, chat with the locals, maybe go kill some monsters in the caverns. You can retire an adventurer, switch back to fort mode, see your old character become one of your citizens, and so on.

I had a go at adventure mode, but I must admit I found it hard to create a narrative for myself. It was fun wandering around and hearing what monks thought life was a bout, but I wasn't quite sure where the adventure was.

Check out http://roguebasin.com/index.php/Category:Roguelike_games , there should be at least a few you find interesting

New versions of Nethack are still coming out, too.

checkout cataclysm dda if you're into cyberpunk