Great question by the way! There are so many nursing specialties out there. Here are some more to list besides the ones you listed:
-Flight nursing, school nurse, critical care nurse, cardiac nurse, oncology nurse, nephrology nurse, wound care nurse, psychiatric nurse, forensic nurse, travel nurse, ambulatory care nurse, home health nurse, operating room nurse....ETC
- Seriously there are a lot and if you want a more in depth description for each of the above which includes their job description, annual wages, required education and more visit this site: http://www.registerednursern.com/nursing-jobs-rn-jobs-registered-nurse-job-openings/
Critical care nurses (aka ICU nurses) probably make the most regarding pay due to the knowledge and advanced nursing skills they must know in order to do their job. Any job that requires advanced skills and knowledge with high stress will pay the most.
I am a nurse and the most rewarding specialty for me is labor and delivery and working with newborn babies. I don't know if it is because I am a woman and naturally love babies but I find it the most rewarding.