As I mentioned before my friend L gave all three of them to me for my birthday and I read them all within a week: Sabriel in instalments on week-day nights and then Lirael and Abhorsen straight-through on the week-end. It was a great rush immersing myself in that world, but very sad at the end of the third book to know that the adventure had come to an end. There is apparently a novella set some time later in the same world, and Garth Nix's webpage does make mention of a possible prequel, so there is hope I will get to visit again...