I like to think of Roguelikes as graphically retarded Diablo clones. I think that gets the point across, even if it is grossly inaccurate.
If, and it is a big IF, you can get over the ASCII? graphics, these games have a depth and complexity that many modern games can't even touch. I mean, some of them have like 20+classes and as many races to play. And the randomized dungeons and loot keep you coming back. There are a ton of variants, like steampunk and anime-flavored. Since I discovered the genre, my 'mainstream' game playing has taken a major hit. No time, gotta send another mindlayer mage to his untimely demise in the dungeon!
This was the world that I had created. I know what I have to do to fix it...to make things right. There's no problem that can't be solved.