Gone Girl

Gillian Flynn’s third book, Gone Girl, skyrocketed to the top of the New York Times Fiction Bestseller list in 2012 and spent 37 weeks at No. 1 (it remained on the list for over 100 weeks). It was named one of the best books of the year by People Magazine and the New York Times, and was nominated for Edgar Award and the Anthony Award for Best Novel.
Which is better: the book or the movie?