What is best is all a matter of perception.for most people it could be what was popular through their teen years. For me it is mixed on the one hand my greatest interest was always big band 1945 through the 50's with a great influence also from the 30's and enjoyed very much so still today. But if I was pushed for an opinion I would edge and say I think the greatest decade would be 1965 to 1975. I also think that as one gets older you still hark back to the days when you listened to music all day and combed your hair every couple of minutes. We all have many great memories and I think that is what makes music not only unique but personal.