Ancient Domains Of Mystery (ADOM) [official site] is one of the first things I install on any computer I own or borrow. That’s been the case since I first discovered the game around twenty years ago. Created by Thomas Biskup, ADOM is one of the great traditional roguelikes, a combination of randomised dungeon crawling and a hand-crafted overworld. There are scripted sidequests as well as a Big Plot to follow, and there are oodles of character combinations.
It’s now available on Steam for the first time, in enhanced form. I roguelove it.