Of course, the best way to get a good answer would be if you first listed some objective measurements first for libertarianism / Objectivism. Otherwise, we can discuss (argue?) about what it is and isn’t till the cows come home without getting an answer.
So, what does Rand in her book, or the common Libertarian think-tanks, or a cross-section of Libertarians, consider useful yardsticks? What other areas would negate a good perfomance in one area?
For example, if you say it’s about people being happy, there is some poll that asks people how happy they feel. Some scandinavian countries rank very high (Denmark and Sweden, IIRC), as some of the small Pacific islands. The scandinavian are very social democratic though, and the islanders have very little material wealth.
Is it about highest number of rich people? Then some countries like Luxemburg and Monaco, or the Bahams, would count, since a lot of rich people move there solely for tax purposes. But their riches were gained elsewhere, so this is probably not in the original spirit.
Is it about personal freedoms as written in the law - then you have to draw a list of what freedoms are important. (You’ll probably run into the usual US/European divide, where most Americans rate freedom to own guns and absolute freedom of speech as highest, where many Europeans rate freedom from complete poverty as high).
Or is it about personal freedoms as in practical real life? Then culture plays a role in it, because the rights of homosexuals or “weirdos” to live unmolested in many areas ruled by fundies is restricted, regardless of the offical laws of the land. Or people with the wrong skin color in racist areas. But this spreads down onto a regional, not a country, basis.
So until you tell us what should be measured, you won’t get a definitive answer, only suggestions and counter-arguments.
Though getting some definitve measurements in the first place might also be an lenghty exercise … 