Republic Online http://www.republic-online.net/
Republic Online is a large online game based on countries and citizens. When you sign up, you will become the citizen of a country. You will have to earn money, pay taxes, get married. This will be your chance to meet other people playing the game and talk, marry and fall in love with them. You can earn money either by having a profession (of which there are a lot, from builder to professional thief), or you run a farm and live off their harvest. If you are a very knowledgeable person, you can always enter the Republic-Online quiz, where you can win money by answering 3 questions.