I just read on another thread that Diana Wynne Jones died in March. 
Guardian obituary
She was by far and away my favourite children's writer. I think The Ogre Downstairs was the first one I read, followed by The Spellcoats, Charmed Life. Power of Three et al.
When I was about 18 I rediscovered her and was (naively) amazed that although I'd stopped reading her, she hadn't stopped writing so I had about half a dozen years to catch up on.
I think Fire and Hemlock was my favourite and I took great delight as a bookseller recommending her reissued Crestomanci novels to children post-Potter.
I wasn't too keen on the couple of adult books she wrote, but her clever, witty, complex children's fiction is second to none. RIP.