, worth $900 million:
Castro reportedly makes his fortune by heading a number of state-run companies, but also through alleged kickbacks from missiles, cigars and rum that run through the Communist island nation.
Click the link to see some other names on the list. One that stands out is Teodoro Obiang Nguema Mbasogo, President of Equatorial Guinea, worth $600 million. Wikipedia says of him:
Most domestic and international observers consider his regime to be one of the most corrupt, ethnocentric, oppressive and anti-democratic states in the world.
It's good to be king.
Update: Volokh Conspiracy has the story, too. The original story in Forbes is here (registration required).