I can only speak to the NASM vs ACE certifications as I do not have the AFPA.
Which one of those is better for your depends on the clients you serve. From a practical orthopedic pre/post rehab perspective, I got more out of the NASM CES. ACE is much more oriented toward cardiovascular, metabolic and pulmonary conditions.
On the other hand, ACE CMES is a full certification with a very challenging proctored test, and you need to re-certify every two years. As such, it wold carry higher weight on a resume. NASM CES is a test that you can take at home (even though they do not make it very easy either).
Hope this helps.