I first read this book ages ago and fell in love with it. Not just the story and characters (Butler, the bodyguard/butler all other Butlers are named for, Holly the feisty, first female LEPRcon officer Artemis kidnaps, Commander Root with his gruff nature, Foal and his foil hats, Juliet and her teenage fascination with wrestling, Mulch the dwarf and his marvelously bodily function) but also the idea of fairies living beneath my feet and the code in gnomish on bottom of the paperback version that I spent time figuring out.
There are 8 books in the series, and I read 6 of them in this past month. They're quick reads, but they also suck you so it's hard to put them down. And the best part about them is the developments Artemis goes through. You can see him grow up, and not just step into the adult world but do so as a genuine good person. It doesn't help that the series covers every thing from time travel to extra dimensions to Atlantis.
Another sweet thing about Artemis and Co is that I actually found myself using the dictionary feature of my kindle while I was reading each book. I learned, and laughed while doing it.