That's an extremely broad question that I doubt anyone can satisfactorily answer.
The people with physics backgrounds who earn the most money are arguably the entrepreneurs who manage to transform an idea born in the lab into a commercial venture. Of course, they also stand to lose their shirts.
After that you're looking at financial modeling-type work... hence the "Wall Street" reply. I don't know how common MSc graduates get involved in that kind of work. My impression is that they're generally looking for the PhD theorist types who have a lot of computational physics on their CVs.
Something else to look into are the "professional physics" careers such as medical physics or geophysics. In medical physics you will certainly need more training (unless your MSc is from an accredited med phys program).
Many people with physics backgrounds will go on to work in engineering, IT or commercial research and development-type positions. You could go to the AIP website to look at their stats on what fields recent grads are getting into.