Hollywood Homely: Louise is anything but ugly yet she's presented as the unpopular nerd who Brad would never notice until she gets a makeover and become popular.
Les Yay: The aforementioned "I Like Boys", which has a bunch of sweaty teenage girls dancing around the locker room in skimpy leotards talking about how much they love boys, apropos of nothing. Yeahhhh,sure.......
Memetic Mutation: "TOP THAT!" - which is the most parodied part of the film and has gone down in reputation as one of the most Narm filled songs ever.
Nightmare Fuel: For whatever reason, Louise's brother is just.....wrong. His weird voice, lolling eyes, grotesque panting, the bizarre almost perverted way he is ogling her birthday cake etc. He goes way beyond the normal jerky, bratty brother archetype to something altogether more......twisted.
"There are good movies, there are bad movies, there are movies that are so bad they're good and then there is Teen Witch — a cult classic that defies classification thanks to a curious combination of songs, spells and skin."
Values Dissonance: If a teacher tried use the same methods to humiliate a female student today, including go through her personal belongings and showing off her birth control pills, he'd probably end up getting suspended if not outright fired.
Vindicated by Cable: The movie was a flop on its theatrical release, but has gained a cult following through airings on TV.