Communism would be far better than democracy if it weren't so easy to corrupt. The way the government is built makes it very easy for the wrong guy to take total control of the country in a matter of weeks.
Democracy, while much less free than a real communism, is decidedly harder to corrupt and so tends to come out happier in the long run.
Monarchies, however, can actually become paradises with the right king. As with communism, though, one bad king can make the citizens lives hell, and so monarchy is derided and abused. Much like dictatorships, which aren't required to be evil (suprise!), monarchies tend to get kings who are corrupt, sadistic, and/or inept, and overshadow the good, just kings who are far more capable than a democratic president of making his kingdom happy and safe.
Using these examples I deduce that while communism and monarchies are superior on paper, democracy is superior at the most important thing; making absolutely sure no-one can fuck it up without trying their balls out. However the effectiveness of a leader to change what his predescessor did is inversely related to the amount of voice the people have. A good king can clean up after his father or other such figure and be able to go forward by next tuesday. A communist leader has almost no chance of fixing anything since evil folk and idiots make up half the population. Democracy is flawed, but the others are too, and Democracy at least makes fuck-ups try to screw it up.
Chance of fixing) Monarchy>Democracy>Communism
Democracy is an anti-hero.