What is the best source for defensive driving course is it online or classroom or DVDs Any one did this course if so please tell you which one is best?

Defensive driving was required to get a license when i was 16 going through drivers ed. I took it in a classroom setting and i'd recommend that over a DVD or online for the simple reason that you can ask the instructor if you have a question, and also that most instructors will give you more and better information than the book will. You don't have that advantage with a DVD.