executive
Legislative, at least most likely
Assuming you're referring to the branches of government in the U.S.A., there are three of them. The Executive Branch includes the Office of the President and an enormous array of federal agencies such as the Food and Drug Administration, the Federal Bureau of Investigation, the Department of Homeland Security, and many, many more. These federal agencies all answer (at least theoretically) to the Office of President, and collectively they are considered all part of the Executive Branch. The Legislative Branch includes the the Senate and the House of Representatives. There are a small number of agencies that are also part of the Legislative Branch, such as the Government Accountability Office, which, though it is a government agency, answers to the House of Representatives rather than the Office of the President. The Judicial Branch includes the Supreme Court and the Federal Court System, which includes federal judges and their support staff.
Legislative, at least most likely
Louisana State University Federal Agency Directory lists over 1,300 distinct organizations across all three branches of federal government: Legislative branch (Congress); Executive branch (President and departments and independent agencies); and Judicial branch (Supreme Court and Circuit Courts). link: http://www.lib.lsu.edu/gov/fedgov.html
Thomas Jefferson was opposed to federalism, which controlled the federal government and called for national banks and tariffs. Jefferson also disagreed with the idea of implied powers which gave ambiguity to what the government was allowed to do with its power. In response to this, Jefferson created the Democratic-Republican Party.
They are all importent if one branch was gone our government would be screwed up
Legislative, at least most likely
The branch of government that is assumed to be least likely to bend to political pressure is the Supreme Court. They should remain impartial and fair at all times.
Legislative, at least most likely
In the United States, all eyes are on the federal judicial branch as at least one ruling on same-sex marriage is imminent in the current session of the United States Supreme Court. There is little action in the legislature and the executive branch has already done all that it can.
Russia did not really have a government system when it pulled out of WW1 because of the Bolshevik Revolution. But before the war the had a Tsar in charge and afterwards chaos to say the least.
For the most part, a person must work for at least 20 years for the federal government to draw a pension or retirement. Employees also contribute to a 401k type investments.