Do you mean "dictatorships", which have a narrow political definition, or "authoritarian governments", whose definition is somewhat wider?
Many a "president for life" is the executive of a nominal republic. Some monarchies are authoritarian, and some are not. Oligarchies can be authoritarian, but can't be dictatorships because a dictatorship places political power in the hands of one person.
To get the list you want, you would need to define your terms more closely.
Technically, the list of three that Rob offered you is correct, but I don't think that's what you're really asking.