One of my brothers used to have 2 ferrets. They've since died, but I got to take care of them for a month while he was traveling around the country with a friend of his after getting his undergrad degree. One of them was pretty lean - your typical ferret - but the other was a bit fat and lazy. They were both fun in their own way, but the fat one was nice because he wasn't quite so fast and was more laid back and let you pet him easily
I think they make pretty good pets and certainly don't see why they should be illegal anywhere.