Goodnight Mister Tom - Michelle Magorian
Bridge to Terabithia - Katherine Paterson
Goodbye Mog - Judith Kerr
No Matter What - Debi Gliori
The Velveteen Rabbit - Margery Williams
Charlotte's Web - E.B. White
Duck, Death and Tulip - Wolf Erlbruch
A Monster Calls - Patrick Ness (see my review)
Michael Rosen's Sad Book - Michael Rosen
The Secret Garden - Frances Hodgson Burnett (see my review)
I have Michael Rosen's Sad Book and Goodnight Mister Tom sitting in my TBR. There is always a book you've never heard of - this time No Matter What.
I would add some other books to this rather excellent list.
The Scar - Charlotte Moundlic (see my review)
By the River - Steven Herrick (see my review)
See Ya Simon - David Hill (see my review)