I am about to embark upon the brave new world of Medicare. What are some of the things I should be aware of? I am admittedly spoiled by currently having great corporate health care. My SIL is pushing AARP (United Health Care), but I suspect her coverage is very pricey. I want to have a choice in doctors, specialists and hospitals, but I don't have to have the platinum plan. What are the best supplemental insurers and plans for good options?