Pimsleur method and Michel Thomas's method are quite similar, based on their descriptions. What are the differences between them?
The Pimsleur program offers courses with more audio time and covering a larger number of languages. Pimsleur is built on a "spaced repetition" approach. Some people dislike that approach when they are asked to repeat the same few words over and over again. Which happens during the first 4-5 lessons of any language program when vocabulary is still small.
The Michel Thomas program offers fewer CDs per level (10, or 8, or 5), as opposed to Pimsleur's 15 CDs (for most languages). Lessons are of different length. Each lesson covers a specific topic and vocabulary set. There is far less "spaced repetition." The lesson is driven more like a classroom lesson where a teacher may spend a long time explaining things without asking any questions.
I personally know people who preferred Michel Thomas courses as a way to prepare themselves for a tourist trip abroad.