Hi,
We stayed at the Lopesan Catarina hotel on the border of PDI and Maspalomas.It has a hotel run kids club for 2 hours in the morning and then for 2.5 hours in the afternoon.It is also a very child friendly with really large rooms and very safe garden areas.It also has 2 childrens pools and a child only jacuzzi.It has a mini disco each night and family entertainment.The food was also very good.

Have you ever been to Playa de Ingles?Depends what you like of course!
It is very built up,busy,and reminds me of somewhere in England.
Melonares is much nicer,beautiful beaches etc.
Lopesan Gran Hotel has kids club...but it is expensive.

We stayed at the Barcelo Las Margaritas a couple of years ago - lovely hotel with plenty going on for the kids, activities within the lovely hotel gardens held throughout the day.
However, I have to say I wasn't overkeen on Playa del Ingles. The hotel was great though, and if I could have picked up the hotel and plonked it down somewhere else, that would have been ideal!