At one time I thought there was a forum for personal trainers... did I miss it or is it gone?

I would like to pick the brains of a couple of pro's on what certifications are decent ones to have.. Not looking for college degree type certification but a program that focuses on training for general fitness I guess you would call it.

I have seen

NFPT
AFPA
ACE
ISSA

and some others but what is the difference and are any of these courses worth the $$..

Thanks

Robert