Pet Semetary - Stephen King. The single most depressing book I've ever read. And I read every word.
The Unoriginal Sinner and the Ice Cream God - John R. Powers. Funny and poignant, with a very distinctive voice. Read more about this here.
Along Came a Spider - James Patterson. Terrific serial killer book, introducing Alex Cross. In my opinion, this is Patterson at his best. And solo, too.
Nathan's Run - John Gilstrap. Great characters and great pacing.