I love how Rosetta stone completely immerses you in the language you are trying to learn. I used it to start learning Mandarin Chinese and this was crucial because any other program was mostly just reading, but Chinese has so many pronunciations that it was crucial to be speaking. It is really effective to constantly be using pictures for form associations, even if you aren't a very visual learning, because you're also speaking and listening. Using every sense like that ensure's the most effective learning possible.

I really like the way it takes you by the hand to learn something new (a language), they have a very good way of going step by step teaching new things

I love the aspect of immersion versus rote memorization. I have found that when you immerse yourself in the language, you begin to gain a more real understanding of sentence structure and gain true fluency.