OpenDungeons

OpenDungeons, a free clone of the classic Dungeon Keeper, is another project to watch. It had very rapid development for a while, then went dormant a period and was recently made active again with a shiny new release. It still has a long way to go to a finished game, but it has lots of potential and the concept is fantastic: As an evil dungeon lord, build and expand your dungeon and invite fierce monsters to keep meddling adventurers away. This project is one to watch in the future!