If you are not looking to stay specifically in Akumal, check out Petit Lafitte. It's north of PDC in Xcalacoco. Haven't been many years,(10 or 11?) but it used to be a small, laid back oasis of calm in that crazy area. However, it is not in the middle of town and is fairly isolated in terms of being able to walk to restaurants. They have (or did have) a pretty good one on site.
The small hotel Caribe and Casitas mentioned are nice locations