5. Saw
http://www.youtube.com/watch?v=b1lgXhFbXy4 Number of films: 7 I debated heavily on whether to include Saw in a list of slasher films because of the infinite arguments against it being one, but I decided it ticks enough boxes to qualify. Once you decide on that, the next tricky question is just how good it is. I for one believe that the entire series, excluding the dire final installment, was an excellent showcase in a more intelligent type of horror film. The original was dark, creepy, well paced and mature, with the subsequent sequels upping the torture and gore but also retaining that intelligent back story and sense of moral confusion the series is acclaimed for. Then Saw 7 (or Saw 3D to use its dreadful cinematic title) used orange blood and a mannequin of Betsy Russell and revealed its only plot twist in the opening scene, killing off the two attractions of the series in one fell swoop. Seriously, the two minute tape of Billy the Puppet they loop at Saw: The Ride makes for better viewing for an hour and a half.