The best place to develop PM skills? Look for the companies that are contractors in your field.
Find a company where their ONLY business is managing/building projects for other companies. These are the companies that are doing it right (regardless of methodology, name, process, etc.). Their very survival is based on their experience and knowledge both in how to accurately bid a project, but how to also bring it in successfully. Because if they can't do those two things then they won't get more business, or they won't survive very long.
So find a contractor that's been around for a while. You'll learn very quickly what's really important. You'll also most likely have both the authority (and responsibility) needed to get it done, which brings it's own set of learning.