If you plan to travel with your family, Dreams Puerto Aventuras is a great option.
It is a medium size hotel with a bit more than 300 rooms, 5 restaurants, 2 swimming pools, a big jacuzzi, kids club, spa and some other services all gathered in one building.
The beach is nice and sandy and the sea is safe for kids as it seems you are in a big 2 or 3 feet swimming pool with almost no waves at all.
The food and the rooms are okay and the staff is very kind in all areas.
If you like to see or swim with dolphins, they are literally 5 steps outside the hotel.
I stayed from July 30 through August the 7th and I would definitely come back to spend another vacations with my family.