The Westing Game I don't think a Lot of People have heard of but the others I'm sure you all have.
I LOVED the Westing Game! I liked how it was put together as a puzzle!
Hmmm.... Have I mentioned The Princess Bride
: Good Parts Version by William Goldman/S.Morgenstern (oddly, there is no other version, and they're the same guy)? It's my favorite more serious book. I say that only because Artemis Fowl and other books that I ADORE are made more for YA and Teen, but The Princess Bride was made to appeal to everybody. And I'm fairly confident it does.
Also Lord of the Flies
by William Golding (strange: two of my favorite authors have almost identical names, but radically different writing styles). Really creepy, but amazing, if you like that sort of thing. The Book Theif
by Markus Zusak. SO amazing. Words can't even comprehend it.
Also I Am The Messenger
by Markus Zusak. This one has a creative plot: A kid named Ed Kennedy recieves playing cards with adresses on them, and for each adress there is someone he has to help. It's also a bit of a love story, and possibly the most feelgood book I've ever read.
And if there was one book that I couldn't reccommend more highly, it's the Abarat series by Clive Barker. A girl named Candy Quackenbush is dissatisfied with her boring life and decides to run away, when in the middle of a feild in Minesota she finds a lighthouse, the John Brothers. Candy is then called on to summon the sea of Izabella out of a cloud, and in the sea she finds herself in the amazing Islands of Abarat. In the Abarat, there are twenty five islands, one for every hour of the day and an extra, the Time Out Of Time. Here time is not just time, it's also a PLACE. But the adventures don't stop there, and Candy soon realizes that while there are bright Hours in the Abarat, there are also those of Darkness.