Using a very broad and general definition of a market.
Least free/most regulated/interventionist:
Education
Energy
Agriculture
Healthcare
Telecommunications
Finance
Freest/least regulated:
Consumer appliances?
electronics?
clothing?
Services?
What do you guys think?
The freest are the black markets of course.
I’m not so sure. Since they exist only because of some type of regulation. Absent the regulation those markets would look much different, would they somehow be less free?
I would vote computer software by far. It’s a technology that, in some instances, just kind of accepts the fact that their code is easily reproducible and can be found free on the Internet with a lot of ease. They are always churning out new and updated products and really serve the people who will use the products. I think there is hardly any regulation of software; it seems to be a very decentralized industry.
Anything with government monopolies (Police, Fire, First Class Mail, Roads, Courts (for the most part)).
Airports are one of most regulated markets as well.
@flic
I think the OP is asking what is freest/least free markets in the present time in the U.S. But even if society removed the regulations, how is the market less free… just because there might be more competition doesn’t mean a market is less free