I know this is an old thread, but I wanted to give my two cents. The Assimil programs are excellent. They claim to bring you to a B2 level. I think that is a little bit naïve. However, if you complete the program according to their instructions (with both the passive and active waves), you would probably be a solid B1. They typically cover all of the major points of grammar as well as a vocabulary of around 2,000 words. They are set up with the format of fun (and often funny) dialogs. I just wanted to throw that out there for anyone wanting to learn a new language.