Of course, children's fantasy from the second half of the twentieth century was essentially launched by two staggering and seminal creations, Tolkein's Middle Earth and C S Lewis's Narnia (the latter never a personal favourite, but undeniably influential). Here are, in my view, some of the finest works which followed on their heels, but in no way stood in their shadows. They were, and remain, great books in their own right. All are hugely enjoyable reads too.
In some instances I have picked out a single book or sequence to represent a writer of several great fantasies.
The towering greats:
Elidor, The Owl Service, Alan Garner
The Dark is Rising Sequence, Susan Cooper
The Earthsea Trilogy, Tehanu, Ursuka K Le Guin (there are also other amazing follow-ups, but they came much later)
The Chronicles of Prydian, Lloyd Alexander
The Dalemark Quartet, Diane Wynn Jones
The Song of Wirrun Trilogy, Patricia Wrightson
Other wonderful, and often influential books, well worth seeking out:
The Prince in Waiting Trilogy, John Christopeher
The Whispering Knights, Penelope Lively
The Young Wizard Sequence, Diana Duane
The Changes Trilogy, Peter Dickinson
The Hero and the Crown, Robin McKinley
Red Moon and Black Mountain, Joy Chant
The Hounds of the Morrigan, Pat O'Shea
Marianne Dreams, Catherine Storr
Fintan's Tower, Catherine Fisher
The Redwall Series, Brian Jaques
Beadbonny Ash, Winifred Finlay
The Wind On Fire Trilogy, William Nicholson
Charlotte Sometimes, Penelope Farmer
The Snow Spider Trilogy, Jenny Nimmo
Boy in Darkness, Mervyn Peake
The Ghost Drum, Ghost Song, Ghost Dance, Susan Price
The Troy Game, a Jean Morris
(I am sure this list will grow as I remember and dig out other books from my reading past.)
At the turn of the century two other massively influential children's fantasy creation emerged, one of great literary merit, the other of (deservedly) unprecedented popularity. They were of course Philip Pullman's His Dark Materials triology and J K Rowling's Harry Potter sequence. It is my quest to seek out the best of what has followed in the footsteps of these two giants that is the subject of my companion blog Magic Fiction Since Potter.