and we haven't started the Dark Is Rising series by Susan Cooper yet, but it's fantastic! Might start spark an interested in Arthurian legend.
If you are moving towards books like Susan Cooper's, you might also like Nancy Farmer's "Sea of Trolls" series. It is the next fantasy series on the list for DS7.
DS7 read alot of mythology back in the fall... greek, norse, robin hood, arthur, versions of the illiad, odyssey etc, etc. This was popular and good for both general cultural literacy and for reading fantasy type books. "Sea of Trolls" is heavily viking/norse mythology based. Mythology could be a hook to make it more popular or it could be a hook to encourage an interest in mythology. Either way, reading kids versions of mythology could be worthwhile.