Some questions for all you Brazilian Jiu-Jitsu practicioners out there: Which "style" of the art would you recommend and why? Which would you consider to be the most effective and complete when it comes to groundfighting? Are there any organisations to avoid and why? What are the differences between the different organisations/schools (such as the Gracies', Moreira's, etc)?

*********
"To enter is to be born, to retreat is to die."
-An Old Taijiquan Saying