Any recommendations in Riviera Maya for a family of 4, kids aged 2 and 5, that is all inclusive is welcomed!

www.paradisus-riviera-cancun.com

www.bookit.com usually has sales

Akumal Beach Resort! Very low key, they love kids there, you can snorkel right off the beach or at the Yal Kul Lagoon close by (great for kids).

There are SO many that it would be hard to list them all. The Iberostar Paraiso complex is great for families.
Go to Apple Vacations and Fun Jet and see what they offer.

A few years ago we stayed at the Paradisus and it was full of kids and everyone looked like they were having a good time. Very large pool. We have also stayed at the Iberostar and that too was full of kids having a good time but it is much larger complex. Depends on what you want. Beach is better at Iberostar Complex.