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.
YMMV: Skyhigh
The Film
Awesome Music: The opening scene is set to "Everybody Wants To Rule The World."
Crowning Moment of Awesome: When the Commander gives the kids and Ron Wilson the hero award and actually refers to them as heroes. Made even more awesome with the “Well Done Son” Guy moment right afterward with Mr. Boy: "Oh, and Jonathan - whatever you're teaching these kids, keep teaching them... it."
Cult Classic: A surprisingly strong fanbase for a oneshot production unconnected to any of Disney's better-known properties.
Designated Villain: Rare protagonist example. We're supposed to see Will as becoming slowly corrupted by his newfound popularity, and neglecting his real friends for people who don't really care about him... but then you realize that every instance where he blows them off was somebody else's fault. He missed his appointment with Layla because his parents insisted on dinner with him and Gwen, he didn't sit with them anymore after transferring to Hero track because Penny wouldn't let him, etc. He could have stood up to them, but that's really his only sin, and yet the movie wants us to think he was turning into a Jerkass.
Die for Our Ship: It happens, Will and Gwen being the most common victims.
Draco in Leather Pants: Lash. He's quite possibly the least sympathetic character in the film, yet he has piles and piles of fanfics portraying him as some sort of sensual lover.
Ensemble Darkhorse: "Freeze Girl" is an unnamed character with no lines, yet she has her own character filter at fanfiction.net and more stories there than Gwen does. Lash also qualifies.
Fan Preferred Couple: A portion of the fandom think Layla and Warren looked better together.
Harsher in Hindsight: In some of the promotional material, Warren was jokingly declared "Most Likely To Become A Villian""◊ in the Sky High yearbook. Then in the actual movie, it's revealed that Warren desperately wants to be a hero and live down his father's reputation.
Misaimed Fandom: Warren fangirls really like parroting the inspirational line he gives Layla at the Chinese restaurant, ignoring the quite blatant fact that this is a parody of such lines, as five seconds later it's revealed he's reading it off a fortune cookie.
Narm: The "Pacifier" thing that temporarily regresses anyone into a baby.
Launcher of a Thousand Ships: Layla. There's a reason both of the Die for Our Ship examples above directly relate to her romantic prospects. You've got your fairly obvious Will/Layla and Warren/Layla of course, but if you do a bit of digging you can find Gwen/Layla and even Lash/Layla, both of which tend to be seriously steamy.
Ron the Death Eater: Will is rarely turned outright evil in Warren/Layla fics, but he's often portrayed as a dull or neglectful boyfriend, and such stories often begin with something to the effect of "Will and Layla dated for three weeks after the movie before Layla broke it off because he's boring." Will is usually thereafter Demoted to Extra or at most paired with a background character. Gwen is also sometimes portrayed as a vapid, "girly" bimboand her Royal Pain persona cranked Up to Eleven to Complete Monster territory (even though in-film she was a silly Silver Age-esque villain who only wanted mass-deaging and corruption rather than mass-murder) to justify Will/Layla. Most of this is done to make Layla look better for whatever choice the author selects for her, if you can't tell.
Steve is also a semi-common victim of this, with his canonical preoccupation with the family name twisted into outright obsession. If Will is gay, he usually gets the obligatory designated homophobe role, too; one memorable fic has him throw Will out of the house upon discovering he's dating Warren, and Will's new father figure subsequently becomes, of all characters, BaronBattle. The story ends with Josie leaving him for Mr. Boy.
Shocking Swerve: A curious example. Gwen's sudden complete personality transplant from cool-if-somewhat-possessive girlfriend to Alpha Bitch had no buildup whatsoever, however, when considered with the film as a whole, a lot of seemingly arbitrary scenes that appeared to have no point suddenly make a lot more sense (the malfunctioning light fixture at the dance, for instance, and also Speed randomly walking in on Will and Gwen as they're about to have a moment). Amusingly enough, a number of reviewers claimed to have called this twist from the beginning, using the logic that senior girls never date freshman boys.
Unfortunate Implications: None of the female freshman we see are sorted into 'Hero' class. Admittedly Layla was only excluded because she refused to display her abilities out of principle.
Also, if you don't have powers, you are automatically designated as a sidekick. Essentially it means in order to be accepted in your own community, you need powers.
The solution to the Have You Tried Not Being a Sidekick? problem is for Will to get powers. Don't read too closely into the potential analogies.
Will going out with Gwen, who turns out to be Royal Pain, who is quite a bit older than Will. Borders on paedophilia if you think about it. He even says after Gwen reveals she's Royal Pain, "Oh my God, I made out with an old lady!". Though it's strongly implied that the only reason she knows she's technically in her forties is because Stitches told her, meaning she's both physically and mentally 17, even with a gap of only three years the relationship has a lot of somewhat disturbing "experienced person taking advantage of inexperienced person" undertones, which, given that she's a villain, was probably the point.
What an Idiot: Who was the fool that thought an individual with the ability to to bend technology and machinery to their will wasn't anything less than a powerful superhero in the making? Short sighted doesn't really cover it.
Possible Fridge Brilliance: If it was the 70s or so, technology might not have been to the point where it was as important/used the same way as it is today, and so the power wouldn't have been seen as being as good.
X Meets Y: X-Men (specifically the Grant Morrison era, where a lot of mutant powers were... less than useful) meets Harry Potter. It was probably not coincidental that the film came out at the height of both Harry Potter's popularity and the superhero movie boom, ignited by, you guessed it, X-Men.
Crowning Moment of Heartwarming: Mai sacrifices her life to save her mother. At the gate, she asks to bring Katou along to heaven with her, despite the fact that he killed her.
