Simulation Games
http://www.gpstore.co.nz/Games/PC-Games/Simulation/?aff=4
FlightGear - Flight Simulator (94 visits)
http://www.flightgear.org/
OpenTTD - a clone of the Microprose game "Transport Tycoon Deluxe", a popular game originally written by Chris Sawyer (56 visits)
http://www.openttd.com/
Railroad Tycoon 3 - (132 visits)
http://www.railroadtycoon3.com/
SimCity - (101 visits)
http://simcity.ea.com/