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.
"Funny Aneurysm" Moment: In the episode where Susan Olsen was being interviewed (circa 1996), Space Ghost's evil twin Chad asks her if shes related to Mary-Kate and Ashley Olsen. He then goes on about how freaky-looking they both are. In 2004, Mary Kate entered rehab for anorexia.
Growing the Beard: The first few episodes sounded incredibly stilted and odd. It isn't until later in the season that the dialogue began to sound more natural, and vastly improved by the second season.
Recycled Script: "Kentucky Nightmare" and "Baffler Meal" are virtually identical in concept (Space Ghost sells out to a fast food company, which injects obnoxious advertising into the show, and Willie Nelson is the guest). However, it's justified in that "Kentucky Nightmare" was intended to replace "Baffler Meal", which the creators never intended to air (but several years later did).
Very noticeable during "Baffler Meal", where Willie Nelson only gets 4 or 5 lines, all recycled from "Kentucky Nightmare".
Seinfeld Is Unfunny: This show was unlike anything else on the air in 1994 and only got more "out there" as the series progressed. Now almost the entire Adult Swim lineup has taken some cues from this show and it's more difficult to see what made it so special.