The Narnia novels were just the right size, big enough to entertain for most of the evening, but small enough to be finished in one night. Most of the books I own are a great deal bigger. Fortune's Wheel, next of the Sholan Alliance series, for instance, is nearly 650 pages. I shall need to be careful, as I have a bad tendency to read "just one more chapter", then looking up and finding it is well past my bedtime. It just annoys me to leave a book unfinished.
I'm not sure what I shall read after the final Narnia book. Perhaps Rats and Gargoyles.