Pioneers (FOSS clone of Settlers of Catan)
Settlers of Catan is a fun board game in which people attempt to build up a certain score by building roads, settlements, and cities. Now, there's not really a computerized version, and copying one directly would be illegal, so, thankfully, we have Pioneers, an open source clone. The source code can be found at Here, at SourceForge. The game is simple, and shouldn't suck too many resources out of the machine. Hopefully, multiplayer functions will be intact, perhaps Ad-Hoc too.