The Abhorsen Trilogy by Garth Nix is one of my very favorite series. Those of us who read Shade's Children (also by Nix) when we were younger might be a bit apprehensive about this trilogy being fantasy instead of science fiction, but Nix writes with just as much ease and force in this hauntingly beautiful series. The three books follow two main characters, Sabriel and Lirael. These young women are fantastic role models: strong yet empathetic, brave yet humanly unsure of themselves, young but growing.
The world Nix has created for this trilogy is complete and believable. Yes, there is magic, and a lot of it, but it is structured and highly organized. Rules have been set down and are followed, and Nix does a fantastic job of weaving this world into a tightly knit fabric.
The plots could move a little quicker, but still these books are very fast reads. Once you pick up any one of them, you'll find yourself an hour later, glued to your seat, having read a hundred pages without even noticing it. Both emotions and actions are described vividly and evocatively. Having just finished the last book for probably the third time, I found myself crying just as I had the first and second times. This is truly a magnificent set of books, and very much recommended for anyone who loves fantasy.