Penguin put out this nice list, which I’ve rearranged here chronologically:
Robinson Crusoe by Daniel Defoe (1719)
Grimms' Fairy Tales by The Brothers Grimm (1812)
Pride and Prejudice by Jane Austen (1813)
A Christmas Carol by Charles Dickens (1843)
The Water Babies by Charles Kingsley (1863)
Alice's Adventures in Wonderland by Lewis Carroll (1865)
Little Women by Louisa May Alcott (1868)
Twenty Thousand Leagues Under the Sea by Jules Verne (1870)
What Katy Did by Susan Coolidge (1872)
Heidi by Johanna Spyri (1880)
The Adventures of Huckleberry Finn by Mark Twain (1884)
Kidnapped by Robert Louis Stevenson (1886)
Black Beauty by Anna Sewell (1877)
The Selfish Giant by Oscar Wilde (1888)
The Happy Prince & Other Stories by Oscar Wilde (1888)
The Great Adventures of Sherlock Holmes by Arthur Conan Doyle (1892)
Moonfleet by J. Meade Falkner (1898)
The War of the Worlds by H. G. Wells (1898)
Just So Stories by Rudyard Kipling (1902)
Five Children and It by E. Nesbit (1902)
A Little Princess by Frances Hodgson Burnett (1905)
The Railway Children by E. Nesbit (1906)
The Enchanted Castle by E. Nesbit (1907)
The Wind in the Willows by Kenneth Grahame (1908)
Anne of Green Gables by L. M. Montgomery (1908)
The Tale of Jemima Puddle-Duck by Beatrix Potter (1908)
Peter Pan by J. M. Barrie (1911)
The Secret Garden by Frances Hodgson Burnett (1911)
Winnie-The-Pooh by A. A. Milne (1926)
Emil and the Detectives by Erich Kästner (1929)
Swallows and Amazons by Arthur Ransome (1930)
Ballet Shoes by Noel Streatfeild (1936)
The Family from One End Street by Eve Garnett (1937)
The Hobbit by J. R. R. Tolkein (1937)
A Traveller in Time by Alison Uttley (1939)
The Little Prince by Antoine De Saint-Exupery (1943)
Animal Farm by George Orwell (1945)
The Diary of a Young Girl by Anne Frank (1947)
I Capture the Castle by Dodie Smith (1948)
The Lion, the Witch and the Wardrobe by C. S. Lewis (1950)
My Naughty Little Sister by Dorothy Edwards & Shirley Hughes (1952)
The Complete Borrowers by Mary Norton (1952)
Brother Dusty-Feet by Rosemary Sutcliff (1952)
Charlotte's Web by E. B. White (1952)
The Eagle of the Ninth by Rosemary Sutcliff (1954)
Mrs Pepperpot Stories by Alf Proysen (1956)
The Silver Sword by Ian Serraillier (1956)
The Hundred and One Dalmatians by Dodie Smith (1956)
Tom's Midnight Garden by Philippa Pearce (1958)
Paddington: Please Look After This Bear & Other Stories by Michael Bond (1958)
James and the Giant Peach by Roald Dahl & Quentin Blake (1961)
A Wrinkle in Time by Madeleine L'Engle (1962)
Where the Wild Things Are by Maurice Sendak (1963)
Charlie and the Chocolate Factory by Roald Dahl & Quentin Blake (1964)
The Giving Tree by Shel Silverstein (1964)
Brown Bear, Brown Bear, What Do You See? by Eric Carle & Bill Martin Jr (1967)
A Kestrel for a Knave by Barry Hines (1968)
A Wizard of Earthsea by Ursula K. Le Guin (1968)
Ladybird Tales: Sleeping Beauty by Vera Southgate (1968)
Charlotte Sometimes by Penelope Farmer (1969)
Mrs Frisby and the Rats of NIMH by Robert C. O'Brien (1970)
Watership Down by Richard Adams (1972)
The Worst Witch by Jill Murphy (1974)
Danny the Champion of the World by Roald Dahl & Quentin Blake (1975)
Dogger by Shirley Hughes (1977)
The Twits by Roald Dahl & Quentin Blake (1980)
George's Marvellous Medicine by Roald Dahl & Quentin Blake (1981)
Goodnight Mister Tom by Michelle Magorian (1981)
The BFG by Roald Dahl (1982)
Matilda by Roald Dahl & Quentin Blake (1988)
Boy and Going Solo by Roald Dahl (1989)
Haroun and the Sea of Stories by Salman Rushdie (1990)
Northern Lights by Philip Pullman (1995)
Zagazoo by Quentin Blake (1998)
Noughts & Crosses by Malorie Blackman (2001)
Eragon by Christopher Paolini (2002)
The Wee Free Men by Terry Pratchett (2003)
The Spook's Apprentice by Joseph Delaney (2004)
Biggles and Co. by W. E. Johns (2004)
The Penderwicks by Jeanne Birdsall (2005)
Percy Jackson and the Lightning Thief by Rick Riordan (2005)
The Book Thief by Markus Zusak (2005)
The Boy in the Striped Pyjamas by John Boyne (2006)
The Arabian Nights: Tales of 1,001 Nights translated by Malcolm C. Lyons & Ursula Lyons (2008)
Nation by Terry Pratchett (2008)
Wonder by R. J. Palacio (2012)
Turtles All The Way Down by John Green (2017)