I was the proud owner of
every single Enid Blyton book. Looking back, I really did have all of them, mostly from charity shops.
This Time of Darkness, by HM Hoover.
Alice in Wonderland/Through the Looking Glass (and other, increasingly drug-influenced stories by Lewis Carol). The Headmistress of my infant school drew me aside one Christmas, when things were bad in my family, and gave me a talk about how I could do well if I chose to, despite everything. She also gave me this book as a private present. It was her own old copy, threading about the binding. Bloody great stories, too.
The Ennead.
Asimov's collections of sci-fi stories for children. They weren't actually written by him, but I only remember the stories, not the authors.
Er, novelisations of Dempsey and Makepeace episodes.
The Dark is Rising and the sequels.
Agatha Christie novels! Well, there were lots of them in the charity shops. I've just recently started re-reading them, again bought from charity shops. I also read my first Mills and Boon novels at that age, and was horrified by the thought that this was what conventional relationships were supposed to be like. Perhaps Mills and Boon were my 'root.'
Jean Ure and Judy Blume. I didn't quite understand some of them till I read them a couple of years later.
Bernard Ashley books.
Roald Dahl, of course.
The Secret Garden. Bolded because I loved it so, so much. The Little Princess wasn't bad either.
Tom's Midnight Garden.
I was late to Pratchett and Douglas Adams.

Didn't discover them till I was in my teens.
The Turbulent Term Of Tyke Tiler by Gene Kemp
My teacher hid this book from me and had specifically chosen it because it wasn't in the local library, and I hadn't read it before, so could only read it in classes and never guessed the twist at the end. I know, I should have guessed, but I didn't.
She had a few other great books too (though she was one of the many authors that I didn't know was female back then - I thought Enid was the only one). I'm sure one of them was televised.