It’s a bit of an eclectic mix, but I would suggest:
Wonder, by R.J. Palacio (although you might need to dig out the Kleenex for part of it);
A Monster Calls, by Patrick Ness (ditto. It's popular at the moment);
'The Fault in Our Stars' and 'Looking for Alaska', by John Greene;
The City of Ember series, by Jeanne Du Prau;
'The Secret Countess', 'A Company of Swans' and 'A Song for Summer' by Eva Ibbotson;
'Goodnight Mister Tom' and 'Back Home' by Michelle Magorian;
The Declaration (series), by Gemma Malley;
My Sister Lives on the Mantelpiece, by Annabel Pitcher;
Skellig, by David Almond;
A Christmas Carol (among others) by Charles Dickens;
(...and you might want to check out Carmen Reid's 'Cross My Heart', John Boyne's 'The Boy in the Striped Pyjamas' and some of the Siobhan Dowd books).
There are also some good suggestions by other posters :)