I don't really have an all-time favorite, but there's one that I thoroughly enjoy... it's called Sabriel by Garth Nix. It's about a girl who learns how to control the Dead using the bells of a necromancer. She herself is not a necromancer, as necromancers are evil people using the Dead to their own advantage. she's the Abhorsen, who puts the Dead to rest. She quickly learns of her inheritance as she tries to go rescue her father from one of the Greater Dead: Kerrigor. i'm not the world's greatest at book descriptions. XD