Empire-An Empire is a government that generally has an Emperor(ess), but that leader can be hereditary or elected. What makes an Empire unique is the fact that it is established usually on its diversity and/or fairness. Empires generally are well respected and age remarkably well. Other types of governments may eventually change into an Empire as time goes on.
Absolute Monarchy-In this type of government, the monarch, usually a king or queen, has total control over the government and answers to no elected body.
Monarchy-In this type of government, the monarch holds most of the authority of the State, but usually answers to a council of aristocracy.
Constitutional Monarchy-In this type of government, the monarch holds little to no power and is just a figure head, while the Parliament makes most of the desicisions for the State.
Republic-In this type of government, power rests with officials elected by a majority vote held by the people. It usually has an elected President as it's leader, though it may vary if it's a President-For-Life or one that serves a certain number of years in office.
Democracy-In this type of government, technology enables the People to vote on all matters almost immedately. The People usually elects a Speaker to represent the democracy in foreign affairs.
Totalitarian Democracy-In this type of government, the people elect a leader for life who then has absolute authority over the nation. Most of the time, all other political parties are outlawed, ensuring little change in the policies of the nation as leaders die over time.
Dictatorship-In this type of government, a single person has managed to gain control of a nation, usually by force. He controls the nation absolutely, but usually with the assistance of the military or a political machine.
Military Dictatorship-In this type of government, the military, usually fed up with previous governments, takes control of of the nation through force and establishes a constant state of martial law.
Military Organisation-In this type of government, there are no civilians. Every citizen works as part of the military machine and has a rank of some sort.
Confederation-Each planet in this nation is virtually independent, but work together for one reason or another. This government keeps the individual planets happy, but generally gives the nation as a has whole little or no national pride.
Federation-A nation formed on the basis of a union of differant races, united in a common cause or purpose.
Criminal Syndicate-A nation where the dominant crime organization grows strong enough to seize power and take full control of the government.
Corporation-In this government, a corporation has taken control of the planet, the entire civilization becomming a part of the massive monopoly.
Theocracy-A government, usually similar to an absolute monarchy or an Empire in structure, which is controlled by the dominant religious organisation and faith. The leader is usually seen as being chosen and directed by a God or Gods, or as being a reincarnation of the past leader. This type of government often incites rebellion by its generally oppressive nature, but in some cases can make the nation more effective by uniting it under a single, strong faith.
Constitutional Dictatorship-A single man rules with the populous able to 'elect' a congress. That congress can impeach the dictator if he is failing the people via a unamious vote, otherwise that single person may rule with an iron fist. S/He would wield complete control of the government.