Paul Krugman recommends universal Medicare

Paul Krugman who writes opinion columns for the New York Times and is a prize-winning economist, has concluded in his May 1, 2006 column Death by Insurance that providing Medicare to all Americans would immediately save significant money, increase the health and welfare of all Americans, remove the anxiety over changing jobs, eliminate the 46 million uninsured, take health care responsibilities out of the competitive equation for business. And as he concludes...
So here we are. Our current health care system is unraveling. Older Americans are already covered by a national health insurance system; extending that system to cover everyone would save money, reduce financial anxiety and save thousands of American lives every year. Why don't we just do it?

Another analysis of the pros and cons of various permutations on health insurance supports his thesis.( an easier to read pdf version can be accessed on the first page)
Strategies to increase Healthcare Access