The Need for Narnia

We finished Prince Caspian, the second book of the Chronicles of Narnia, this weekend.  I'm really happy that the kids have gotten into it as much as they have.  They normally like anything we read to them, but they were especially intrigued with The Lion, the Witch and the Wardrobe and as soon as we finished it several months ago they clamored for the next book.  I wanted to pace them out so we read a few other things in between, including Alice in Wonderland, which the kids found boring, and Stuart Little, which thoroughly irritated me, but all the while they were pleading for Narnia. 

Once they got to launch into it they were just as pleased with the second book as they were with the first, though N seemed pretty preoccupied the whole time with the potential return of the dreaded White Witch.  ("She's dead, N.  Don't worry about it."  "But, but, but, but maybe she's not all dead.")

They know there are more books awaiting them, but I want to keep stretching things out, so I'll be looking for something else to plug the holes.  Any recommendations?