Since I have not heard any suggestions about what order to go into more detail about the specific genres covered in True 20, I have decided on the following: Fantasy, Modern, Space, Horror. This seemed like a logical progression to me; for the most part this is moving through time from less advanced to more advanced. Horror is being covered last as elements of this can be applied to any other genre.
Tag: True 20
The Revised Edition of True 20 by Green Ronin is a simple, yet very extensive gaming manual. The contents cover every setting imaginable and allows for a great deal of customization.