According to the reference desk at the John F. Kennedy Presidential Library & Museum, these were President Kennedy's favorite books as a child:
Arabian Nights
Billy Whiskers series
Kidnapped by Robert Louis Stevenson
Treasure Island by Robert Louis Stevenson
A Child's Garden of Verses by Robert Louis Stevenson
King Arthur and the Round Table by A.M. Hadfield
Lays of Ancient Rome by Thomas Macauley
The Jungle Book by Rudyard Kipling
Kim by Rudyard Kipling
Bambi by Felix Salten
Uncle Tom's Cabin by Harriet Beecher Stowe
Peter Pan by J.M. Barrier
Black Beauty by Anna Sewell
Story of a Bad Boy by Thomas B. Aldrich
Wing and Wing by James Fenimore Cooper
Biography of a Grizzly by Ernest T. Seton
At the Back of the North Wind by George MacDonald
Pilgrim's Progress by John Bunyan
Wonder Tales From East and West Introduction by Maud Wilder Goodwin
--Marshal Zeringue