The various books by Kenneth Oppel; possibly more on the Sci Fi side, but never the less, all very good.
http://www.kennethoppel.ca/pages/books.shtml
I initially read Airborn, Skybreaker and Starclimber before moving on to most of his other books.
The bat series (Silverwing, Sunwing and Starwing) was also most enjoyable. Darkwing could be considered a prequel to that series.