My favorite subgenre of horror is the slasher film. Where else can I gleefully watch a montage of sex, drugs, and violence without being deemed a social degenerate? The slasher film entertains on such a primal level that it skews the viewer's perception of right and wrong. The ethical self wants everyone to enjoy their prom night and get home safe, but the primal self wants a hulking, masked maniac to crush the fat kid's head so that his eyeballs land in the punch bowl. In 3-D. It is through this moral subversion that murderers become heroes -- ringleaders guiding us through a carnival of carnage. We all know the names: Jason, Freddy, Chucky, etc., and we all have our favorites. I'm a Jason fan, through and through, but who is objectively the best? More importantly, who is the deadliest? To answer this question, I have devised a simple ranking system, based on what we will be calling "KPF" or "Kills Per Film." The KPF ranking is a simple average derived by dividing a slasher villain's total body count by his number of film appearances. In the cases of Norman Bates and Hannibal Lecter, their television shows are each counted as one movie. Remakes and reboots are also part of the total. While it can be argued that reboots are not part of the original storyline and should be counted separately, it can also be argued that I don't really like math and I don't want to do any.
At the bottom of the ranks is Norman Bates (with the help of Mother) with a KPF of 3.4. While his style of slaughter is much more subdued than some other folks on this list, he is by no means safe to be around. Then again, if creepy roadside motels are your thing, you may be rolling the dice already.
Next in line are Hannibal Lecter and Leatherface, with a KPF of 4.2 and 4.4, respectively. I like to imagine that an escaped Dr. Lecter spent the night at Bates Motel, had Norman for dinner, and after a bit of car trouble, ran into Leatherface and became dinner himself. Unfortunately for Leatherface, his big meal has left him sleepy. He dreams of a burn victim named Freddy Kreuger, who has a 4.6 KPF. Freddy gleefully notes that in another place and time, he and Leatherface could have been good friends. Then he kills him with his knife fingers.
Chucky the Good Guy Doll, complete with 6 fun phrases and the soul of a serial killer, finishes with a KPF of 5. Not bad for someone without knees. Even with properly jointed limbs, Chucky would be no match for the Leprechaun, who averages 6.4 kills per film. Perhaps Chucky would be more dangerous if he hadn't settled down and started a family.
In fourth place, with a KPF of 7.3, comes the Candyman, but even he can't escape the grasp of our next killer, Fate. Yes, the villain from the Final Destination series does fulfill all slasher requirements, and with a KPF of 7.8, is one of the most dangerous. I'm tempted to say that Fate is the most effective killer -- perhaps the hands of every cinematic slasher was moved by Fate, each franchise under the St. Elsewherian snowglobe of Final Destination.
Second place goes to Michael Myers, and deservedly so. There is no presence on screen quite so terrifying as The Shape. His complete lack of emotion adds a layer of coldness that is unmatched in any other franchise. He doesn't even seem to elicit fulfillment from his brutality, murdering only out of reasonless evil. Even though he failed at killing Busta Rhymes and Josh Hartnett, Michael Myers is never anything less than terrifying. He averages 12.3 kills per film. Season of the Witch was not included in the numbers.
The shining gold medal goes, of course, to my main man Jason Voorhees. You can run, but he'll catch you. You can hide, but he'll stab you through the wall. You can drown him, blow him up, even toss him into the vacuum of space an he will always return with new and creative ways to kill sexually active teenagers. Even when factoring in his absences from Friday the 13th (Mom did it), and A New Beginning (the paramedic did it), and factoring in that a few of his kills exist only in virtual reality (Jason X), he still manages a whopping 15.1 kills per film. Not bad for a zombie with mommy issues. The iconography of Jason Voorhees is indelible. When you see that mask you think of murder, not hockey. For thirty years, Jason Voorhees has been cutting through America's youth with a machete. He has literally been through Hell and back. There's no reason why Jason won't hold his ranking as the deadliest film slasher for years to come.
Note: Ghostface and Jigsaw were left out of this assessment because Ghostface is multiple people and Jigsaw doesn't actually kill anyone. Splitting hairs, I know, but I cite my aversion to math once again.