Chances are you've already heard of The Girl With the Dragon Tatoo, and for good reason too. Written by Steig Larsson, this is one of the best books I've ever come across.
The book follows Mikael Blomkvist, a journalist who has fallen on hard times after being framed for libel, as he sets out on a mission to solve a forty year old cold-case of a missing girl. With the aid of a young, misunderstood genius, who holds a few authority issues: Lisbeth Salander, Blomkvist turns over stone after stone seeking answers in this fast-paced thriller where nothing is as it seems.
I'm usually not a fan of thriller books, but I absolutely loved this thriller. Breaking the cliches and often tired plot lines of most books in this genre, Larsson defines just what a great book can be. This is the first book in a three part series by Larsson; and while I haven't read the others yet (plan on doing so soon^^), if they're anywhere close to as good as this book, they'll be well worth a read.
tl;dr Awesome book, check it out.