The Palms generally uses the dive shop at Ramon's Village, which has a good reputation and is close by.

You'll (probably) get lots of recommendations because people generally like the dive shops they know. "divingcowgirl" is very complimentary to us (Protech) but if others bother to post you'll probably get similar comments about other dive shops. As Elbert says, you'd really have to be very unlucky to find a bad one!