@Patricia - I like Assimil with audio MP3. I used "La méthode Assimil" (French version) for beginning Arabic, Korean, and Japanese. Assimil provides practice with basic information (alphabet, sound system, common verbs) in an enjoyable way. After getting a basic foundation, regular textbooks or other learning material are easier to master.
@drasvi - I agree with your points completely. One note, Patricia probably used method as a bad translation of the similar French/Spanish/Portuguese word meaning "instruction book." In French "La méthode Assimil" means the instruction book by Assimil.
I used it to learn English and Spanish, and now Russian.
I think it is a very good one to learn with ease, in particular the grammar and vocabulary. The only negative point in my opinion is that it could be a little bit boring sometimes because you always have to do the same thing everyday.
I would recommand it to start learning and then, combine it with other ways like traveling, listening to the radio, music, tv...