I enjoy "The Kingdom Series" as well as it's sister Series "The Knights of Arrethtrea" by Chuck Black. Another series I enjoy is the "Tales of Redwall" by Brian Jacques. Of course there is also the "Inheritance Cycle" by Christopher Paolini, "The Chronicles of Narnia" by C. S. Lewis, and of course "The Lord of the Rings" by J. R. R. Tolkien. All of them are great books though I don't know many people who haven't at least heard of the last two. If you want a more modernistic fantasy try "The Giver Series" by Lois Lowry. The fist book doesn't have much of a fantasy element to it but it becomes more fantasy as the series progress.