Sure, these were ASCII-based, randomly generated, viciously deadly little dungeon crawls with only a hair's chance of winning, but that was, somehow, part of the fun. It's been forever and a day since I played...until yesterday, when I was introduced to Dungeon Crawl: Stone Soup.
All the fun of the originals, plus more. Deeper, more polished, more options. Playable in ASCII mode or with a graphical tile set, with no loss of game feel. Yes, it's simple, yes, it's nothing compared to the games of today..and it's still a metric ass-ton of fun. if you ever enjoyed them before, I urge you to go give it a whirl. Hell, it's open-source and free, man, go for it.
Speaking of open-source and free, LibreOffice 3.3 is available now. if you ever liked OpenOffice, this is the way to go.