I'm not very good at roguelike games, but nevertheless I like to play Brogue. Unlike some of the best-known traditional roguelikes like Nethack and Dungeon Crawl Stone Soup, Brogue is fairly minimalist, and achieves a significant strategic breadth from relatively few game mechanics and item types. For example, it does not have races or classes, gods to worship, special dungeon branches, or an enormous amount of tactical trivia to memorize.
Brogue was created by Brian Walker (AKA Pender) but nowadays the canonical and actively-maintained version of the game is a community-developed fork called BrogueCE. You can play it in a Web browser without downloading anything.
Brogue has a few notable variants, two of which are particularly interesting: gBrogue and Brogue Lite.
gBrogue was created by Gregory S. Reed and aims to enhance Brogue's strengths by encouraging liberal and creative use of consumable items rather than stingy inventory management. To this end some items are combined while others are removed entirely. gBrogue also adds a variety of new elements while attempting to preserve the elegance of the original game.
Brogue Lite, by HomebrewHomunculus, is a very straightforward revision of Brogue. It removes the game mechanics of item identification and cursed items along with any items that have no beneficial use (except perhaps in rare edge cases). To compensate, the overall rate at which items are found in the dungeon is decreased somewhat. Playing without these mechanics convinced me that they were never that interesting or fun in the first place.
A game I would really like to try, though, is gBrogue Lite. Sadly, there is not yet any version of Brogue which combines the ideas of gBrogue and Brogue Lite. I would create it myself but I suspect it would be beyond my modest programming abilities.
Brian Walker on procedural level design