1. Shenzhen (dafen, dongmen, seafood street, shekou, ritz carlton, hyatt....lots to do....wutang mountain).
2. Guangzhou (heaps of things to do.....brilliant german restaurant on the river!)
3. Zhuhai (maybe full of old people?!!)
4. Dameisha (nice Hyatt there on the beach front)
5. Kaiping (3 hours from Shenzhen by bus) beautiful old style chinese buildings....
6. Lamma island
If you go onto the HK government website there have info about camping, holiday places and private accomodation on many of the islands......worth a shot!