The nicest all-inclusive place I have been to is Excellence Playa Mujeres. Its north of Cancun and an easy cab/ shuttle from the airport. The beach is gorgeous and flat and overlooks Isla Mujeres. There are no fat people there binge eating. Its mostly honeymooners. The suites are modern and large, the food is very good, tons of top shelf liquor, adult only, and there's free porn 24X7 on several TV channels.
If you splurge a bit on the Excellence club rooms you get beach valet service and a few other perks.
There's not a lot to do other than kick it on the beach and fully relax...but that's usually what I'm after.
http://www.excellence-resorts.com/ca...-playa-mujeres