When I moved to Guatemala for my job, I needed to learn Spanish quickly. Rosetta Stone was way too repetitive, dull and tedious. Pimsleur as well. I came across Michel Thomas's method, by chance, and cannot think of any other way to learn a language. Known as the language teacher to the stars, Michel Thomas has a method that I connected to instantly - one could say it's kind of based on fuzzy logic at times. Generally, though, the method breaks up a language into pieces, and through seemingly real lessons with real folks, Thomas presents those pieces to you in a way that builds on your previous knowledge. By the end of a track, you've learned something new and can apply it in everyday conversation. I still have yet to get through my advanced lessons, but it's clear there's a sequence (present tense, basic sentences to past/past participle sentences with varying structures, etc.) and any repetition is deliberate and purposefully layered on things previously learned in the course.