This is a tough one. There are so many genres to choose from!
Andy Weir's The Martian is my favorite science fiction book.
Bel Canto by Ann Patchett in general fiction.
All the books in Dennis Lehane's Patrick Kenzie and Angela Gennaro series. Gone Baby Gone is my favorite of the bunch, but don't let the movie deter you. Casey Affleck is so not Patrick Kenzie.