These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Common Knowledge: Jason never used a chainsaw, despite the fact that he is often depicted in parody work doing so. In fact, it is the preferred weapon of Leatherface. Jason's canonical weapon of choice is his machete.
To the point that one of the most in-character actions of Jason X is him hunting for his machete for the first third of the film and abandoning the future machete he's been using up until that point when he retrieves it.
In The New Blood Jason did use a gas powered underbrush cutter on one of his victims. Not a chainsaw, but still...
Some people think Jason only ever walks, which is true for the second half of his films, however in the earlier movies he was shown running fairly frequently.
Draco in Leather Pants: Believe it or not, it's been done to Mr. Voorhees. He has an astonishing amount of fanfiction where he falls in love with the one girl who he doesn't kill. Frequently going through Wimpification and becoming a literate mentally sound gentleman who just happens to go on mindless merciless killing sprees now and then.
Ensemble Darkhorse: A few minor characters proved quite popular among fans. Some examples would be Crazy Ralph from the first two films, and Violet from A New Beginning.
It's the Same, Now It Sucks: Parts two to three can come off as this, as they all have very similar plot structure. Later films get more creative with their presentation, though some of them disliked for getting too creative.
Narm Charm: The majority of Jason X, if not the series as a whole.
Nightmare Retardant: Jason's status as a often referenced popculture icon has turned him into this. Kind of ironic, really. Think about it: if, in Real Life, you found yourself being pursued by a relentless, pissed-off, virtually indestructible mass murderer who was built like a pro athlete and wanted nothing more than to bury a machete in your head, wouldn't you be just a little bit scared?
Rooting for the Empire: Most of the protagonists in these films are too boring or unlikeable to care about, so who wouldn't want Jason to kill them all off?
This typically comes into play from the fourth film onwards. The third film has elements of it, but they're still a minor compared to the relatively decent, likeable protagonists — we have three random bike gang scum types, and one obnoxious practical jokester (who admits he only does so because he's a fat nerdy loser type and it's the only way he can think of to make people like him), compared to a pregnant woman and her loving boyfriend, two friendly, quiet-natured hippies, a traumatized girl and her boyfriend, who tries to understand why she's such a wreck. And in the first two films, the councillors are generally pleasant, affable folk, who only count as jerkasses because they see nothing wrong with smoking, drinking or premarital sex.
Sequelitis: With 10+ films, it was bound to happen.
What an Idiot: Why did Jason bother going into the lake if he couldn't swim, anyway? Admittedly, he was running away from his tormentors in a panic, but surely he could have run into the woods, which he knew much better?
Key words there; he was being chased and he was panicked. People don't think too well in that kind of situation to begin with, little kids moreso, and add in the fact Jason was born mentally deficient...
The NES video game:
Awesome Music: The game isn't really good, nor is the music anything to write home about. But years after its release, Ghetto Lee Lewis (a contributor for Overclocked Remix) got his hands on it. Let the results speak for itself (the sound samples contain spoilers for the first movie, though).
Paranoia Fuel: Jason could occasionally show up unannounced inside one of the cabins that you were investigating for items and notes. And once you're inside with him, you're locked in until you face him.