Edge-of-your-seat thrillers where nobody…least of all, the main characters…knows what's going to happen until the tense finale. The audience might be able to spot the plot's MacGuffin (a term popularized by the genre god Alfred Hitchcock), but the fun is in finding out how it all works itself out and bragging about how early you had it all figured. These are the films that really define the mystery/suspense genre.