Funny, I was just thinking about Gilligan's Planet this morning. With all the criticism of Filmation, I was running down the list of its shows, and I think it is more of a mix, as stuff like Fat Albert, Archies, and the Batman/Superman now playing on Boomerang didn't seem any worse than any other TV cartoon of their period. I likes Lassie, and somewhat the Brady's, and Shazam/Isis and of most of the sci-fi shows were memorable. (Especially Star Trek) Of course, He-Man, was probaly the one show they produced, that critical cartoon fans of today liked (even though I was so/so about it, not being as much into action adventure). 1975 was a bad year, as they had been turned down rights to animate a M*A*S*H series (which they probably would have done well), and instead created their own "MUSH" spoof, along with Waldo Kitty, and one of their few original ideas, Wacky and Packy (They used to play these all together on "Groovie Goolies and Friends"). Then the Ghost Busters, which I don't remember at all, but 10 years later was ripped off by the movie and its cartoon series. I particluarly thought of the New Adventure of Gilligan (which ran a second season into that year) was a good representation of the original show, but then to move them to a planet in space was a bit ridiculous and showed a lack of ideas.
I too was turned off by many of these little characters they used to add. (including Orko, Bat Mite, etc), and of course, this became a fad that spread to the other studios (As I say, Scrappy is actually the least annoying or mushy-mushy of these). It seems this may have been influenced in part by Jiminy Cricket (why would he need to be added to the classic Pinocchio story?), plus the kids-and-animals concept popularized by Scooby (Jonny Quest and the other HB super adventures were the prototypes of this, with kids and animal sidekicks) and more child-oriented "lovey-dovey" atmosphere this promoted.
I still say Rubik is the worst, and definitely fits the criteria listed --"A series is based on (a popular toy...", etc.