Worst witch books are fab. I so wanted to be Mildred Hubble when I was that age.
I am a bit out of touch with age ranges and reading as DS is only two but I loved reading as a child and loved:
101 dalmations
stig of the dump
the secret garden
Astrid Lingred (sp) books - Karlson on the Roof, The Bullarby Children (sp), Marnie
I think around the right age.
If you go to a big bookshop the staff will be able to advise and will be able to suggest new books you may not have come accross