The Michel Thomas method for Mandarin Chinese by Harold Goodman is well worth a look.
It's worth a BIG look. Best I've used yet. Two courses, basic and advanced which cover grammatical concepts and then there's a vocab course, too. The method Harold uses to teach the tones is something that will stick with you.
I also bought this book which is fantastic again for learning pronunciation and tones of characters.
Unfortunately, as with all the things I do, novelty wore off after about three months as I had no Chinese people to speak with (the ones round here are Cantonese). I really want to pick it up again in the new year.

But I will deffo be checking out the suggestions in the thread and see what works