Gregor the Overlander by Suzanne Collins
Having really enjoyed Suzanne Collins' Hunger Games and Catching Fire (desperately waiting for Mockingjay to come into the library!), I went searching to see if she had written any other stuff and discovered the children's series - The Underland Chronicles.
I quite enjoyed this. It took a bit to get into, but it wasn't long until I was engrossed in the story of Gregor and his quest in the Underland.
Collins' has conjured a marvelous world. I love authors who can take the ordinary - cockroaches, rats and bats - and make them extraordinary. And who can resist a quest!
I'm looking forward to the sequel and discovering what happens next to Gregor, Boots and the rest.