We are looking for a hotel along the coastline south of Cancun (Riviera Maya?) that would have a good beach with snorkeling, good food, and be located conveniently to other attractions along the coast.
It is our understanding that most are all-inclusives.Even so, we still like to go out to dinner, 3 or 4 times at nearby restaurants.

You don't say what caliber resort you are looking for. If you are satisfied with a three str resort, the Akamal Beach Resort has a gorgeous beach with good snorkeling right from the shore. It is all inclusive, but is inexpensive enough that you won't feel bad walking into town for some "local" food.

There are many places that are not AI. If you want to go out to dinner and not have to drive look at the towns of Playa Del Carmen, Akumal and Tulum. For snorkeling right off the beach I would look farther south than PDC but then you will be limited as far as the number of restaurants/bars as the town is much smaller. Not to say that that's a bad thing.

Thank you for your responses. We prefer more of a 4 to 5 star type resort, (using Apple or Funjet standards).
If I could pose my question another way, what are the favorite hotels of people who have stayed along the coast south of Cancun, and for what reasons?

WE love the IBerostar resorts. They have wonderful service. Activities all day if you want them or you can just sit and relax all day.
For more info on resorts in that area try:
http://www.locogringo.com/forums/default.asp
or
http://www.playa.info/playa-del-carmen-forum/