According to two major economic freedom indices[0][1], the US is ranked 18th and 10th, respectively, worldwide. So no, I wouldn't say that the US is the "most libertarian country in the world".
Canadian here. My country is listed higher than the US in both lists, but I have to laugh out loud at that. Canada is swimming in protectionist laws that choke off competition in some vital sectors, like telecom. Even Amazon got crap for wanting to open warehouses here, because it was considered too "threatening" (as in, people might shop there) to the protected, Canadian companies. Canadians routinely cross the border to shop in US towns that are close to the border, because we don't get gouged as much there, and the choices are far better than we get here.
Candadian who moved america: America just has it's own special brand of protectionist crap. Americans often buy their medication from Canada due to all the crony capitalism that the USA has encountered with their health care system. Don't get started on the whole corn subsidy SNAFU.
Also the USA has cheaper shopping compared to most of the world. Few places are cheaper, especially for goods that are not food, clothing or similar.
Canada is primarily a resource economy. Minerals, oil & banks take up a majority of of the TSX's value. Symptoms of Dutch Disease are prevalent inside canada itself.
I'm particularly amused when American regulators try to claim that one should not purchase drugs from Canada, because their safety can't be verified. Really.
Every rich nation has a complex web of mercantilist measures in place, for sure.
0: http://en.wikipedia.org/wiki/Economic_Freedom_of_the_World
1: http://en.wikipedia.org/wiki/Index_of_Economic_Freedom