What is the most libertarian country?

No but the United States was originally founded as a Libertarian state. The term was not yet coined but the basic principles were the same. Over the years various politicians have transformed the U.S. government and entwined socialist principles so the United States is the closest to having a Libertarian government but cannot truly be considered Libertarian. FYI: Libertarianism calls for the bare minimum of government not complete anarchy as many people have misstated.