Face it, there is no 'one' best, however there is 'experience' that will allow you to choose the best method for the circumstance. I've used almost every method, process or product (some were a poor choice) mentioned here and I still have to do it over again sometimes. As to the 'rust converter or rust eater' question, consider the downside of the products too. Read the reviews, and remember sometimes it's not worth the effort if the metal is really bad.
Jim