The Mists of Avalon is definitely the best retelling of the Arthurian legend I've ever read. This historical fantasy book is in a league of its own. I can highly recommend this book to all fantasy fans. It's very entertaining and well written - in other words, it's a great book.
If you like historical fantasy books and haven't read The Mists of Avalon, you should read it as soon as possible. You'll probably like it very much.
By the way, the other Avalon books aren't as good as this book.