[johnswamps]

Great site. But if you're interested in roguelikes I'd suggest starting with Dungeon Crawl: Stone Soup instead (http://crawl.develz.org/wordpress/). Nethack's really showing its age these days and is missing a lot of key features. Crawl is more accessible to newcomers and is less tedious to play. But it is very much a roguelike in the spirit of Nethack.

[kibble]

I agree. NetHack has heritage (and nerd-cred) going for it--but in terms of raw playability, DCSS has it beat, hands-down. Crawl might also be the most active modern roguelike in terms of development (a rotating cast of a dozen+ active developers working consistently over several years), whereas, to my knowledge, all the modern NetHack forks are the works of lone developers.

For players new to roguelikes, I'd also have to recommend DoomRL (http://doom.chaosforge.org/) as a fantastic game, and its shorter length might appeal to more casual players.

[waterlesscloud]

I've spent far too much time playing the Android port of Angband on my phone.

[guard-of-terra]

Seeing as comments turning into a list of roguelikes:

ADOM is one of the best roguelikes. It's closed source but very deep and high quality. http://adom.de/

POWDER is a little graphical roguelike targetted at portable game consoles and PDAs. But you can play it from PC. It's reasonably quick and have a very fun and orthogonal skill/spell/item system. http://www.zincland.com/powder/index.php?pagename=release

[JoachimSchipper]

TOME (http://www.te4.org) is ADOM-ish (reputedly, haven't seriously played ADOM) and pretty fun. I found the level generation a bit repetitive, though.

[guard-of-terra]

I thought TOME is Angband-ish, isn't it? It's a very different branch of roguelikes.

[bhickey]

I'd like to add that the crawl devteam is really friendly and receptive to patches. Development is very active and I find it tremendously good practice to read a codebase that's been developing for the past 14 years.

Just today the team took a patch of mine to simplify poisoning!

[ido]

And if you find even Crawl too intimidating, you can try my roguelike - Cardinal Quest - whose Classic edition is now free to play on Kongregate:

http://www.kongregate.com/games/idoyehi/cardinal-quest

[jcmhn]

I suggest brogue [http://sites.google.com/site/broguegame/] as a better starter roguelike. It looks nice and plays like a dream.

[aw3c2]

Also POWDER: http://www.zincland.com/powder/

Graphical, short and really easy to get into. Runs on a multitude of platforms, also GBA and other consoles.

[kleim]

Lost Labyrinth is a nice graphical roguelike. Games are relatively short but it has a high replayability. http://www.lostlabyrinth.com/