No type of government is perfect. They all have their flaws.
IMHO the best government is one that allows for people to live peacefully and safely, without fear of either other citizens or the government ruining their lives for arbitrary reasons. It is a government that allows for social and legal change as the needs and demands of the citizens change, and it is one that does not allow one group to dominate another simply because the other might be unpopular or politically weak.
We can point to thousands of ways in which our government is imperfect, but if it does the above things, I think it is good government and the thousands of criticisms doesn't change that.