This extraordinarily successful text for introductory Spanish places an emphasis on communicative proficiency. The method used, called the Natural Approach, stresses the use of activities in a natural and spontaneous atmosphere and grammar as an aid to learning rather than as the focus of the course.
For my Spanish 1 and 2 courses. Honestly a very good textbook, although heavy on content and not-always-translated explanations. I think I'll be using this as a reference in the future, probably mainly for the vocab, and the visual tables for conjugation in various tenses and forms.
Oh! And this is (a different edition but) the Spanish textbook they use on season 1 (and maybe some of season 2) of Community! You can even see Senor Chang's lesson plans and stuff he writes on the chalkboard are taken from the first half of the book!! I totally geeked out when I figured that out this year!