The Boy Who Lost Fairyland

My personal favorite along with the first book.

Brilliantly written, with many nostalgic parallels between Hawthorn and September. As someone who didn't really like the third book, I think taking a momentary respite from Fairyland and September is a wise move. Following Hawthorn's adventures in the human world not only gave me time to recharge, but also brought back the magic and whimsical delight when he eventually found his way back to Fairyland. It revives so many memories of September's first visit.

Also, Combat Wombat. I want one for myself.