Gone Girl is a really interesting movie.  It's certainly a mystery movie, with rising tension and increasing loads of evidence being piled in the audience's mind, and yet I didn't feel as much relief when the mystery was solved as I usually do.  I think this was because the mystery becomes increasingly obvious (on purpose), and the audience is still left to wonder what really happened at the end of the movie.  The ending is also not what I expected at all, and I honestly don't think it really fit Ben Affleck's character.  It will probably be better on a second watch, I'll have to see.  Still a great Fincher Film, and I will definitely be watching it again in the future.