Looking at films and television...
In 2012 a group of friends and I continued in our a tradition of celebrating Halloween by watching three films from the top Slasher film franchises, after watching the first 3 films of these series a year earlier. we moved onto the second films from the Halloween, Friday the 13th and A Nightmare on Elm Street series. Of these three only Friday the 13th Part 2 has been tested against the Slasher rules.
Friday the 13th Part 2 (1980)
The second Friday the 13th film begins by killing the Final Girl from the first film, which considering how dull she was is a bit of a blessing. It then gets into managing to simultaneously both move on from and rehash the first film. Alice's weird dream ending seems to nonsensically be partially true, Jason is still alive, meaning that his mother was committing revenge for pretty much no reason. But now he's out for revenge for the death of his mother (caused by her getting revenge for his non-death) having spent years hiding in the wilderness worshipping her but not actually going to visit her. And the revenge comes as killing off those at a nearby camp counsellor training camp in revenge for the much earlier murder of her mother by a camp counsellor. Alice is replaced as Final Girl by Ginny Fields (Amy Steel) a much more interesting, stronger and better acted character. She's also a smarter character, being able to explain the complicated plot based on surprising accurate guesses and an Intro to Psychology course. And she has sex (maybe) and drinks without being killed.Echoing Ginny as a better Final Girl and Jason Vorhees is a stronger killer than his mother. Ignoring the tangled explanation and less of a mystery/twist compared to the first film, these two make better opponents. The rest of the film is more generic. More teens, more deaths, more sex and nudity make for a bigger but not necessarily better sequel.
The film is undermined, again, by a "it's still out there" ending, which not only the fate of the killer, but one of the victims undetermined.
Halloween II (1981)
The film continues directly on from Halloween (1978), and so while not revealing any more of the mystery it seems to undermine the mystery of the first film. Continuing the same night seems to accentuate the more-of-the-sameness that sequels always risk having. Laurie Strode is forced to go from a survivor (in the first film) to more of an action hero breaking the audience connection. The result is a film so memorable that, although I've seen it a couple of times I always have difficulty remembering any type of detail from it, except that it decides to close the book, leaving it with no "it's still out there" ending.
A Nightmare on Elm Street 2: Freddy's Revenge (1985)
Together... both Halloween II and Freddy's Revenge are weaker than the first films in their respective series leaving Friday the 13th Part 2 - which is, on average, about equal to Part 1 - to keep things interesting. With Friday the 13th Part 1 being the least of the original three films this makes for a far less satisfying night. There are probably as many so-bad-they're good moments, more evenly spread over the three films this time, but there's also a lot more dullness over the set. Still worth watching if you could sit through the first three together, but if not, best to be avoided.