The Isle of Wight is a great place, I spent a lot of my childhood summer holidays there :). Off the top of my head I would recommend Blackgang Chine (bit pricey but children love it), Amazon World (handy if the weathers bad as a lot of it is undercover) Carisbrook Castle, Osbourne house and the Needles on the coast. Theres an ice rink too (I think in Ryde but not sure). There are lots of beaches-Colwell beack I think is very sandy and quiet.If you can defiantely take/ hire a car as public transport is not great.