I fear that many (most) of the modern arthurian novels are inspired by Le Morte d’Arthur 🙂
If you are looking for something very close to Le Morte d’Arthur (like an adaptation or retelling) Steinbeck’s “The Acts of King Arthur and his noble knights”, Sutcliff’s “King Arthur trilogy” and “The Story of King Arthur and His Knights” by Pyle are excellent!
If you are looking for novels that maintain that magical Christianism you can find in Morte d’Arthur then Cherith Baldry’s “Exiled from Camelot” is also amazing, and so is Phyllis Ann Karr’s “Idylls of the Queen”. Both these novels are actually inspired by episodes that are not in Le Morte d’Arthur, but I think they are the best example of the feeling of magic mixed with chivalry and Christianism that you might find in Malory’s work.
Arthurian Legends 