I've never read Dreamland. I think that's the only one I haven't read of her books. My favorites are The Truth About Forever, Just Listen, and Someone Like You. Let me know what you thought of Lock & Key when you're done.
Jeff Vandameer's 'Shriek: An Afterword.' This is one of those books that's beautifully written, with marvelous detail and original worldbuilding...and totally didn't hold my interest. It was like a fantasy writer decided to write a literary novel. I have respect for his talent but this just didn't do it for me.
I have this kind of book-picking luck--I've never read a book I disliked. Sure, I have found some of them a bit generic or uncreative, but that didn't stop me from enjoying them (quoting the Inheritance Cycle and The Spearwielder's Tale here). However, I have like 10 tons of unread books, so who knows.