Dwarf Fortress

[Human No More]

I know Eltu and Thorinair play, but wonder if there are any others

It is a completely epic game, really open ended - you control a group of dwarves, initially only a few but it rapidly becomes a whole city's worth. You create a fortress, you can really do what you want, it's completely open ended, whether that's make a huge industry, or build some crazy megaproject, or just flood the map with magma

It can be fairly hard to learn, your first few fortresses WILL starve to death, get wiped out by goblins, get flooded, have your dwarves all go mad and kill each other... but that's all part of the 'fun' and learning experience - once you know the game, it get simpler and you can soon start making actual successful fortresses

Official site: Bay 12 Games: Dwarf Fortress
Wiki (spoilers. mostly clearly marked): Dwarf Fortress Wiki

More about the game (hidden spoilers): Dwarf Fortress - Television Tropes & Idioms

One recommendation I have is to use a tileset, greatly improves the graphics and makes them much more readable over the default ASCII ones.
the best tileset is here: http://mayday.w.staszic.waw.pl/df.php - just download the latest version which is a copy of DF with it installed.

A few things for starting out:
DF2010:Quickstart guide - Dwarf Fortress Wiki
Tutorials - Dwarf Fortress Wiki
Game Basics - Dwarf Fortress Wiki

Of course, if you have any questions, ask away
This game really is addictive once you've learned it...