Mike's Song is amazing. Full Stop.
No quarter for Skreech or Fred Durst. Because the world needs health care professionals and cooks. You can't figure out when you've been show the door and continue to demand or orchestrate public attention and clog up the entertainment industry with nostalgia and garbage, you deserve to be ridiculed by your former audience, but never by those who seek to co-op you. They're human garbage too.
Seinfeld absolutely deserves to be in the top 10. He's the heat sink of Seinfeld, no one else can be cool w/o him but he uses his status to call shots he can't or shouldn't.
I'd add James Bond Jr. to the list. This was an early 90's cartoon with a toy line that posited a world where James Bond had a son, who also grew up to be a spy, that also has to do battle with most of James Bond Sr's defeated enemies, mostly from the 60's. Odd Job is re-imagined from an Asian butler in a tux, to a Black butler in a track suit. The reason he was a worst character, James Bond Jr. was a happy spy. The antithesis of a good James Bond, an anti-hero that is boozy and a murdering sexist. James Bond Jr. was a gateway toy line for young dudes to wrap their head around the fact that James Bond is a hero. Appalling piece of animation.