Michel Thomas's, the Pimsleur series, and the Barron's version of the Foreign Service Institute course are the three top-selling courses on Spanish, and I did extensive research on the various high end courses before buying his. I don't have the Pimsleur one but I did buy the U.S. Foreign Service Insitute course in addition to Thomas's, and so I thought I'd make a few comments by way of comparing them in case you find them useful in choosing the right course for you.I have to say Thomas is a gifted teacher and he has a very interesting approach requiring no notes or rote memorization. He also stresses the importance of a natural, stress-free learning environment. Thomas is a savvy guy here as this is probably one of the major stumbling blocks for the new language learner, and so he puts the student at ease right from the very beginning--a nice touch there and I give him points for that.The second cornerstone to Thomas's method is the simulated classroom environment where you work along with two other people in the class, a man and a woman. The third, and perhaps most important aspect of Thomas's course is his memorization and note-free system of learning. Thomas starts with very simple sentences and builds up from there so the student acquires the syntax almost intuitively as he goes along. Thomas also discusses differences in pronunciation as he goes, too.You build vocabulary as you go along also, with Thomas empasizing cognates or words that are almost identical in the two languages initially. Overall, Thomas has done a very nice job here and I can see why people like Woody Allen and others say that his course is the only one that's ever worked for them.The Foreign Service Institute course is more traditional but also very good, and I like it, too. The audio tapes present the sentences and conversations while you follow along with the manual/workbook, which provides the translations. The workbook is very extensive and also has a more detailed discussion of the grammar than you'll get with either the Thomas or Pimsleur courses. There is an advantage to this since, although I think Thomas's method is probably fine for teaching the basic verb conjugations, such as present, past, and future, you're really not going to get a good idea of how the several subjective moods work in Spanish without some systematic study of the grammar there. English has the subjunctive, but it's practical a vestigial construction, but Spanish has it in spades and is a very active part of the language.On a side note, it would be interesting to see how Thomas's approach would work for a language with much simpler grammar than Spanish or French, such as Turkish or Japanese. Turkish has the wonderful distinction of being one of the few languages with no irregular verbs, and Japanese only has two. So at least as far as the verbal systems are concerned, they are much less complex than your typical European language, and the Indo-European languages in general. There are a few other more technical aspects to the two languages, of course, such as the case system in Turkish (which Japanese doesn't have), but verb conjugations are usually the most difficult aspects of the languages in most of the popular European ones because of all the irregular forms. And Spanish has at least 22 common verbs that are irregular in at least the present indicative tense, and many are irregular in several other ways.One other thing the Institute course does is to provide substitution drill sections where you're required to substitute a particular word, and then give the sentence, with any needed changes. This is useful for practicing the verb conjugations and other things. I have a pretty strong background in grammar and linguistics in general so I don't mind slogging through dry discussions of grammar too much, but if you're not someone who enjoys that sort of thing, Thomas's approach may be the one for you. Overall, this is an excellent course from a talented teacher with a unique approach to language learning. 

Question: What do you think about background?
Answer: Michel