A single-payer system would be offer the best cost/benefit in terms of providing the best health cased outcomes to the most people. It is the best choice for the United States. However:
Single-payer will not happen for at least 20 years because the political and cultural opposition to it is so deeply entrenched, and the people who would lose money and power as a result of it are so wealthy.
Single-payer offers the real opportunity to vastly reduce the amount of money spent on health care, and the people currently receiving that money can and do fight to keep it from happening.
Challenge Matisse Enzer to a bet on this prediction!