I enjoyed the movie before I read the books... then I LOVED the books and disliked the movie.
The books span months and help the romance blossom, where as the movie spans the course of maybe a WEEK and just makes Scott look like a pathetic guy following a bitchy girl.... It made more sense, really, for Movie Scott to end up with Knives. They actually had common interests, character development, and at the end of the film, it came full circle when they both fought the main bad guy together, similarly to how they played the game in the first act. It's as if the writers and director decided they'd focus on their OTP.