Caves of Qud is quite good, though a bit less traditional in being a big open world vs a dungeon. There a few quirks and bugs but the game is very fun and creative, and it has excellent music. I also love the graphics but it is an acquired taste.

I played the Dwarf Fortress roguelike mode several years ago, and it was really more of a toy - nifty to play around with the mechanics but too dry and arbitrarily difficult to be a fun game. But almost all the dev focus was on fortress management, maybe they’ve spruced up the roguelike with the Steam release.