Glittering Stardust... Until the end...
In 2007 I read Stardust by Neil Gaiman (writer of MirrorMask) and it's really a good book. I think it would appeal to any Labyrinth fan. I love it but I don't care for the epilogue. I know a lot of people like to compare it to The Princess Bride but I think it's actually closer to The Last Unicorn.
The main character, Tristran, is the son of a mortal and a slave kept by a witch in the realm of faerie. The story begins in a town near a wall that separates the magical world from the human world. When there is a falling star Tristran promises to retrieve it for a girl he is infatuated with. He is unaware that the star has taken the form of a young woman in the faerie world and that there are others after her too. Three elderly witches who want to use her heart to become young again, and some bickering princes.
It's a really good story and it has a relatively happy ending except for the epilogue
Ending Spoilers:
It LOOKS like they lived happily ever after except Tristran is aging, Evaine is not. Tristrain eventually passes away and we find out that Evaine pretty much pines for him for the rest of time. What the Hell was the point in telling us that, Neil?! It as fine until that little bit at the end. It's like Oscar Wilde's The Star Child. It reads like a sweet faery tale until you get to the last few lines.