I agree with almost everything that Quag and Dawh have said, and I'd just like to add my two cents:
While it is impossible to have a perfect government as long as it involves imperfect humans, and while most people greatly dislike many of their governments' aspects, it needs to be remembered that without government there is only chaos. Governments allow at least some peace and cooperation in what would otherwise be a violent, unsafe, primitive, brutish world.
Of course, totalitarian governments are not any better than complete anarchy. There has to be a balance between freedom and oppression. With human nature an unavoidable obstacle, democracy seems to be the best solution.
Taxes and our other duties as citizens are needed to keep these institutions running. They are the prices of having some chance at "life, liberty, and the pursuit of happiness." Furthermore, by not doing these duties, you are essentially saying that you are revoking your citizenship. Thus, you are an "illegal alien," and the government has the right to remove you via prison; you also have no right to the benefits of citizenship if you fail to do your part.
Now it seems we're stuck between two evils: support a government with which we disagree or rebel against an institution that gives us safety and peace. The solution? Do our part as a citizen to make our government and our nation the best it can be, including voting, expressing opinions, giving support, and, most importantly, creating unity.
My wise political quote: "United we stand, divided we fall."