Cozumel:
Nachi Cocum ( my favorite) Very quiet and relaxed. Nice beach and pool with plenty of loungers and shade, food and all drinks (alcohol too) included. Okay off-beach snorkeling (fee if you do not have your own). No water park. About $60 per person, kids are less
http://www.cozumelnachicocom.com/
Mr. Sanchos (my second favorite) Fun and active. Nice beach and pool area, not as shady near the beach as Nachi Cocum. Food and all drinks included. Ocean floating park for an additional $12 per person. Add-ons like jet skis, parasailing and horseback riding are available. Okay off-beach snorkeling (fee if you do not have your own) About $55 per person, kids are less.
http://www.mrsanchos.com/
Playa Mia (excellent reviews from friends) Fun and active, not as shady near beach as Nachi Cocum. Food and all drinks included. Pools, fresh-water water park and slides and an ocean floating park included. Also, non-motorized boats like kayaks and water bikes. Add-ons like jet skis and parasailing. Okay off-beach snorkeling (fee if you do not have your own) About $60 person, including all the kids.
https://www.playamia.com/