K.M.
Sorry- late post, but I recommend the Iberostar resort in Playa del Carmen. It's about a 40 minute drive from Cancun and they will send someone to pick you up at the airport.
Wonderful service, many things for all of the family to do (they had a kid's olympics while we were there), craft huts, beach volleyball and more.
Food was good, plenty to drink, plenty of beach chairs- it was a perfect chill week! Enjoy and have fun!