Honestly, I found Charmed Life and The Many Lives of Christopher Chant moderately interesting, but then I really loved The Magicians of Caprona and Witch Week, which I believe are the two that come next.

The internal chronology doesn't match the publication chronology -- The Lives of Christopher Chant was written after The Magicians of Caprona and Witch Week. I don't like TLOCC as much as the other three, but it seems to be a really individual thing.