While ACSM and ACE have been around for a long time and are recognized and respected, there are several other certifying organizations,as suggested in the responses, that offer high quality education. Best bet is to check with the facility(s) where you want to work to see what is required. As far as I’m concerned any education and higher level training you pursue is quite valuable.
It is important to note that NCCA is not the only organization that accredits fitness certifications. Another organization is DETC (Distance Education Training Council), which accredits AFAA.
To give a little background, DETC is an organization recognized by the Council for Higher Education Accreditation (CHEA), which in turn is recognized by the US Department of Education. So you can visualize this:
AFAA -> DETC -> CHEA -> US Dept of Education.
For what it’s worth, CHEA also recognizes many organizations that accredit universities, such as the Southern Association of Colleges and Schools. Both of my alma maters (University of Georgia and James Madison University) as well as the university where I work (University of South Alabama) are accredited by SACS. You can visualize this:
University -> SACS -> CHEA -> US Department of Education.
Here is a link from the International Health Racquet Sports Assn (IHRSA) with recommended, accredited fitness certification companies. AFAA, ACE, ACSM, and many others are listed:
I have both ACE and AFAA fitness certifications. I do think that ACE has gone on a large marketing campaign to state that NCCA-accreditation is the only way to go. NCCA-accredited certs are one way, but as you can see above, it’s not the only way. I’ve never worked at a gym that didn’t accept both ACE and AFAA.
Getting a Certification that is NCCA accredited will make you far more employable. I’d say at least 90% of your better facilities at this point require that you have one of those certifications to be employed as a personal trainer with them. Which one at that point is just a matter of how you want to focus your training style.