I honestly and truly do believe that this is the greatest personal computer game of all-time. The hours that I have spent playing it attest to this. If you like Roguelikes, take up this wonderful game and enjoy all the continued development of it.
This is the hardest and perhaps most addictive roguelike dungeon-crawling game you'll ever play, free and written in '95. It has a fantastic community of players and, to my knowledge, is one of the more popular roguelikes in existence
You can choose between 20 races and more than 30 character classes. Puts Diablo's weapons to shame
Also worth noting – when you die your character is dead forever