For the past few months I've been playing NationStates. Anyone else here play it? If you don't you can check it out at http://www.nationstates.net. Its a free game where you create your own country, respond to the many issues of a growing nation, and watch its progress. You can be a left-leaning democratic state, or a total dictatorship. You can also join the UN and take part in world issues.
EDIT: Fixed url.