chilli said:
Castro for one.
Castro was a great leader.
Sorry I'm not going to make a full list for you.
I'm a fan of Fidel Castro myself. During his time in power, Cuba has developed a medical system that few countries can duplicate and the level of literacy is one of the highest in the world. And Castro's done this while his country has endured a punishing U.S. embargo that has hurt the Cuban people for decades.
Forty-eight years ago today (January 1, 1959), the Cuban revolution forced General Fulgencio Batista to flee the country. The Batista regime, one of the most corrupt ever seen in this hemispere, ruled over the country with an iron fist, outlawing elections and keeping the population in abject poverty, all with the blessing of the United States because Batista was strongly anti-Communist. There's no question in my mind that Cuba has been much better off with Castro at the helm than if Batista and his successors had remained in power.
All that said, if you're a perceived political enemy of the Castro regime, I doubt you'd be inclined to think of it as a benevolent dictatorship. You'd most likely be in prison or in exile. So in a sense, I suppose you're right. There is such a thing as a benevolent dictator, just as long as everyone in the country is on the same page with the same goals and willing to give up personal freedom and the ability to voice dissenting thoughts.