I really think it is rather spurious to speak of ANY existing nation-state as even being close to being a libertarian country. The US is far from being one, it has evolved into a semi-fascist police state that is attempting to run the world. That is why I call it the American Imperium, and refer to George W. Bush as being its President-Dictator.
No country will ever truly be free. If we want a truly laissez-faire society, with truly free markets - and I know that I do - then we need to abolish the state, period.