Reading about FTL and the wait until SRR and SRO got me back into roguelikes. I'm sure there are others around who are skilled, persistent, or self-loathing enough to also play. For those who don't but clicked the link anyway, they are frequently turn-based hack-and-slash games that have randomly generated loot and levels. Most have some sort of xp system, and most are freeware (donate if you like them). ASCII graphics are not necessary. Here are some interesting ones I've tried, please add your favorites:
DoomRL: It's Doom, the first person-shooter, except 2D with an overhead view and turn-based. Also, you gain experience to get better with different weapons or survive better. The game can be won in an hour after a few tries, which might interest more casual players. The 5 difficulty settings from Doom are here, so you can get beat on as badly as you want. There are also achievements and challenge modes for people who are into that. Achivements can be beating the game in 15 minutes, beating it on a particular difficulty or challenge mode, or not using any weapons. Challenge modes force you to use a particular weapon, carry around fewer power-ups, or play though 100 floors instead of the normal 25. Aside from being able to choose the difficulty (which should be more common), the game has an intersting dodge system (move right before they fire a missile/fireball and maybe not get hit), as well as music and tiles. You can actually get a good idea of where enemies are and what type they are by the noises they make.
Prospector: It's a space exploration game, just like Star Trek. Except for profit, add a bit of dark humor, and without the pesky rules about not interfering. You start with a fairly cheap ship and some random gear at a station. Like the game says, hit d to dock. At stations you can buy gear or a new ship, sell data and resources you've collected, hire new crew members, and get augmentations for your crew at the medical station. The station you start at also has a locker with some space suits for those planets without earth-like atmospheres. Any of the corporations (up to 3) will pay for your data and resources as well as loyalty bonuses for not selling to competitors. Resources are laying around on planets (or in completely natural and safe tunnels under them that never contain rooms full of killer robots). Data can be finding stars (and the planets that orbit them), maping a planet by walking around, or by collecting biodata from alien plants and animals/people. Sometimes animals will kill each other so you can collect data from autopsies, sometimes you get corpses from defending yourself from the various vicious animals (some are actually friendly, but all are called vicious), and sometimes they trip and fall on your bullets/lasers. There are black market shops that will buy aquired artwork or sell you illegal military-grade augments. You can also make a decent profit as a trader or on the stock market. The game features sounds and tiles, as well as a save system (no permadeath). Being one of the space pirates is also an option, but a bit more difficult.
ADOM: It's been a bit over 10 years since the game was updated, but a large amount of fan donations got updates going again (also, there is work on a java-based sequel). It's a fairly complex fantasy roguelike, with a world map that is always pretty much the same. Levels are persistent after you've visited them, except in the infinite dungeon. More depth=more difficult, and some dungeons have higher difficulty than others. Character generation is partly random (birth signs and possible random events), partly chosen by the player (class, race, and a question system that impacts stats). Once you get used to using spoilers to figure out what everything means and to get the character you want, it's a pretty decent game. A hunger system, mutations that happen to you over time, and enemies that get tougher the more of a type that you kill all to keep the player from grinding too much. It features ASCII graphics, keyboard support, and probably more spoilers than Nethack by the time you reach level 2. The game is old, but still has a lot of fans. It has to have something great about it, right?
ASCII Sector: Not quite a rogelike, bit similar enough. It's Privateer, except in ASCII and somewhat randomly generated. You can improve character skills for use on planets by using them frequently (useful for later assasination missions or just mugging people), otherwise improvements come from upgrading your ship. You make money by flying from planet to planet trading goods they need for goods they have an excess of. You can also pay to become part of a trading guild to fly a trade route with a certain type of supply within a certain amount of time, join the mercenaries guild to protect merchants, or find fixers in bars who need you to ship something (sometimes illegal goods), save someone stranded outside of their ship, or kill someone. The game gets pretty repetitive, and later upgrades take a while to earn. Until then, it's an interesting game. The game features ASCII graphics (hence the title), and a reputation system with various factions.