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: The Magic School Bus
Adaptation Displacement: The TV show is better known to some than the original books; in fact, a new series of paperbacks went into print based on the TV episodes.
Dark Fic: A more depressing than dark example as a Flash Animation, following Ms. Frizzles class the following school year. No longer being in Ms. Frizzles' class, Arnold is an abusive and foul-mouthed jerkass, Tim and Ralphie are both potheads, Carlos continues to tell horrible jokes only to be beat up (by Arnold) for it, and none of them seem to carry any sort of social skills or even rudimentary math or general education (outside of science, of course).
Ear Worm: The theme song, and the leitmotif of the start of each field trip that derives from it.
Hilarious in Hindsight: In "Out of This World," aired years before Pluto's demotion, the class is rehearsing a play about the solar system where they each play a different planet, but Dorothy Ann is late, so they had to start without her planet... Pluto.
Launcher of a Thousand Ships: Arnold. He's been shipped with everyone- Wanda, Phoebe, Tim everyone in his class, Ms. Frizzle, Molly Cule, that guy from the hot cocoa episode (Harry Arm), that girl from the water cycle episode (Tiffany), Janet, Azula...
Also, footage from the show seems to be popular for YouTube Poop (although, given the Nostalgia Filter protection the show has garnered in North America, it's probably affectionate more than anything).