Thomas Hobbes believed we needed a strong government, preferably an absolute monarchy, to protect the people from their own brutish and violent instincts. Karl Marx envisioned the "withering" of the state and a "dictatorship of the proletariat."
Hobbes, who wrote Leviathan in 1651, a period of civil war and instability in England, thought that only the power of an absolute monarch could keep chaos in check. He wrote that people will live in a state of ungoverned anarchy until constant warfare and instability gets to be too much. Then they will—or in his opinion, should—give themselves to an absolute monarch, who will make all the decisions in the state and even have absolute power over the life and death of the citizens. This would be good, according to Hobbes, because it would bring peace and security.
Marx witnessed the abuses of the Industrial Revolution, in which more and more people went to work in factories with no protections on the hours they worked. In his time, there was no minimum wage, no minimum work age, and no safety regulations—all of which allowed the factory owners to become very rich, as they paid the workers next to nothing and thus made huge profits. Marx thought the only way the people could become free was to revolt against the owners. Like Hobbes, Marx had a dark view of human nature, especially when it was subject to and influenced by capitalism (he was more likely to think of people as innately good when free of capitalist ideology): however, he thought it was impossible for workers to actually negotiate with the owners, because the owners would betray them every time. He thought armed revolution was the only way for the workers to obtain the economic resources they needed to be free.
Marx's perspective is a bottoms-up view of history. He believed justice could only come when the people at the lower end of the economic ladder had control of the means of production. His ideal state was run by the workers, and eventually all forms of governance would disappear as private property was abolished and everyone produced and consumed according to their abilities and needs. People needed a period of re-education, but could then function without a state. Hobbes, on the other hand, had a top-down view of government. He believed everybody, including the poor, would fare better under an absolute monarch and strong centralized state control.
The lessons of modern history have shown that dictatorships of any sort, be they of the masses or a messianic leader, tend to not work out very well, and a happier political state comes somewhere between the poles of Hobbes and Marx.