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.
The Short Circus have a song called "We Love Chow", in which they put on fat suits and sing about how much fun they have overeating.
J. Arthur Crank refers to Spider-Man as a "funny book" a number of times in the show, evidently unaware how more mature the comic would become as time progressed.
Harsher in Hindsight: The Adventures of Letterman short had a villain, the Spellbinder, whose primary mission was to wreak havoc by changing letters of words into new words, causing humorous situations ... for the most part. However, there were several episodes that, while when aired in 1974-1976 might have been seen as funny, would have such situations classed as terrorism today. These include Spellbinder changing "plane" into "plant" (by changing the "e") and causing it (the plane had dozens of children on it) to fall toward the earth; and removing the "b" in bridge to create a "ridge" and a way for a high-speed passenger train to fall into the crevice and kill dozens of children. These segments would be banned from television after Sept. 11, 2001.
Values Dissonance: The Punctuation Brothers sketch begins with three grown men entering a little girl's bedroom through her window. After they give the girl a lesson in using different punctuation marks, the girl's mother finds the men in the bedroom. Instead of calling the police, she expresses thanks to the brothers for helping the girl with her homework. It's implied that the Punctuation Brothers often break into children's houses.
Three episodes in a row (the last three of Season 1) seem to give off a shared aesop of "Never trust or befriend anyone who has been bad but seems to have changed his ways, since they'll always turn out to still be douches in the end."
The episode about Lisa's colonial ancestor, who was believed to be a traitor. It looks like it's shaping up to deliver the reasonable aesop that if an ancestor or family member does wrong, it doesn't mean that you are a bad person. But nope, Lisa's ancestor is revealed to have been a hero all along, which leaves one with the impression that having an ancestor or family member who did something wrong is a horrible fate and shouldn't ever happen to a good person.
Rooting for the Empire: The members of the Pranksters (except for maybe Francine) are arguably much more entertaining to watch than the members of the Electric Company.
They Changed It, Now It Sucks: Fans of the original thought a revival sounded promising, as the 1970s version used both short and long segments to deliver both knowledge and entertainment at no cost to either...but then they heard about all the changes, especially the part about using full-on stories and actually requiring the viewer to pay attention throughout. (Although to be fair to the new show, the fact they want viewers to increase their attention spans is actually a pretty noble cause.)
What an Idiot: The Pranksters. They're supposed to be evil, but their only ambition is (as stated in the pilot) to "take over the neighborhood". The town/city, fine, as at least then you've got at least one position of actual power from which you can try to bring other places under your control...but the neighborhood?!