First thing that comes to mind for me is everyone from Lamb Chop's Playalong, but there's context here: all the characters were voiced by sheri lewis and when the show hit it big she was praised as some super skilled talent. The thing is, the voices all suck. They're all tiny variations of her own voice similar to Adam Sandler in Eight Crazy Nights. Add to that the show's original songs, which were clearly all designed to get kids to annoy the living shit out if adults as much as possible (i.e. The Song That Doesn't End).
I also need to mention this bizzare trend I noticed on shows like Adventure Time and Stephen Universe where they add in all this original music but they use it to have the characters straight up sing the plot. So instead of metaphor and interpretation you get lyrics like "The day that I met you I felt so scared but we fought against this specific bad guy and that changed my mind." Its fucking bizarre and makes it feel like there's some hidden conspiracy to weaken the thought processing abilities of kids watching the show.
So yeah there's a whole swarm of annoying for ya.