RE: The Mists of Avalon, Mists was written, then the prequels were written, presumably to capitalize on Mists's success. Mists is brilliant, but neither prequel is really much worth reading unless you are bored. They're not bad, but they they don't come close to Mists.

Many of the classics listed so far bore me to tears (Austen?! snore!), but Alexander Dumas is always great fun to read -- there's more than the Count out there!