There's a problem with answering this sort of question since it's mostly about subjective and abstract concepts of "good" vs. "evil". What is good? If a dictator takes over two ruling clans and unites them into a single nation, thus stopping years of fighting, is that good? What if his dictatorship involves a secret police, civil rights violations and yearly executions? Is it still good? I mean, less people are dying, but their lives are better, right?

Take pre-revolution Mexico, for example. Porfirio Diaz did a lot to "advance" Mexico into the modern age, building railroads and turning Mexico city into a modern city. Is that a good thing? What if that came at the expanse of thousands of poor farmers who had their lands taken to build railroads on and their taxes used not to better their own lives but those of the citizens of the capital? Are railroads good or bad?

You could compare pre-Mao and post-Mao China and notice a decrease in Opium consumption, and indeed Napoleon's civil codex kinda formed the basis to a lot of nationalistic and liberal concepts during the 19th century. Does that make them "good"? Does that justify their actions? Historians don't usually deal with that, and I hope you can now see why