Yes I don't think I'd use a parametric setup for many of those - perhaps 2 at most. But all can be done with standard poly modelling techniques, and some can be started with splines in various generators, or use various deformers at some point in their construction, but most will probably have to be made editable to get refined and finished off nicely. Topology is very important to a lot of these sort of forms so we do need to pay constant attention to edge flow and when subdivision is ideal (and more importantly when it is not) to make sure we are getting the right sort of tight clean results.
Now I could show you, in various levels of detail how to model each and every one of those, but life, time and forum space is short, so how about you pick one that most intrigues you and we'll work on that ?
CBR