We have that one too. It is very visually appealing.
In terms of other educational books, we like Diane Draze's Red Hot Root Words and others in that group (she has at least one sequel). For math, we're quite fond of Edward Zaccaro's books.
I haven't come up with the $ for the Descartes Cove CDs yet, but they do look interesting. I'd like to give a try with the Art of Problem Solving online math classes at some point, too, but it isn't in the budget right now (and time is limited as we are partially hsing dd#2 and dd#1 is still in school ft).
