I pretty much had every major textbook there was for Legal, not that there are too many out there. But from my experience, the only ones worth having for band 6 results are:
1. *The Leading Edge*(so fucking good. Not to be confused with "Leading Edge")
2. Heinemann.
3. Board of Studies past exams student responses series. Get your hands on as many of these as you can from school/public libraries and photocopy all band 6 essays relevant to your chosen focus studies. Highlight chunks of information that you did not know and any neat vocabulary worth adding to your essays for further sophistication. This will set you apart from the rest of your class.
The Leading Edge is without a doubt the best study guide for Legal Studies. Because it is only sold at a few major book stores (I got mine at Dymocks on George St), and not as well known as textbooks such as Heinemann, it will give your essays that extra edge. It is written by top teachers from well-performing schools who know exactly what markers want and thus only provide you with information that you need for top-notch responses. Non of that wishy washy fluff that I found to be prevalent in Excel. This textbook is honestly the best $30 I have spent in preparations for the HSC. It puts extra focus on areas of the syllabus that the other textbooks and study guides fail to cover in adequate detail (esp. law reform, issues and key questions - all areas which are widely and frequently tested in the HSC. All other textbooks are rubbish at these areas when you compare them to TLE). Another major selling point is their *very* up-to-date law reforms and court cases. If you want to give yourself the best chances of getting a band 6 in Legal with minimal cost, this book is a must have.