My list of least fav cartoons will be from the 90s to current as that is what I am most in the with. I didn't watch WB or FOX much as a kid, so I don't really know the cartoons they had, though I am sure a lot would not be my optimal choices. There are many shows I didn't watch or didn't watch enough of and didn't like I didn't include on this list. I tried to choose shows I watched enough of to know about.
Shows I didn't like...
Bobby's World - I hated the intro theme song and I couldn't stand Bobby's voice! To me it just wasn't a show I connected with or enjoyed.
Muppet Babies - One of those shows that babifies it's characters.... it's happened to a lot of shows. I didn't like muppets much to begin with, but this just took it to a whole new level of dislike.
Beetlejuice - As a kid, I just didn't like this show at all. I didn't like the color palette and I found Beetlejuice himself to be unnerving, annoying, and gross. He creeped the heck out of me as a kid!
Dennis The Menace - Just wasn't an interesting cartoon to me. I read the Sunday comics, but the show was so forgettable.
Garfield and Friends - So.... I liked the show. I liked the GARFIELD part. I HATED the Barnyard friends part and never understood why it was in the show to begin with?! Why? Just make it Garfield! I don't care about a chicken or pig and all those other characters, like that egg with legs!
Pound Puppies - I thought it was dumb as a kid. Even then I remember the acting to be horrible and the animation was so cheap. Though I liked the jacket of the main character. Heh. I remember that.
The Real Ghostbusters - This show creeped me out because of the character designs and Slimer! I could not stand Slimer! He was so gross to me and a big deterrent to when this show turned on, I turned it off.
Pinky and the Brain - So my child self didn't like this show. I thought Brain and Pinky were very uninteresting even though they had some strange adventures. To this day I know all their famous quotes, but the show back in the day was not on my favs list. Still isn't.
Family Guy - I could say the early seasons were good, but when things took a twist into simply sex, gore, and political rants, I lost all joy for the show. It became toxic and not something I particularly enjoyed. I still laugh at the horrible jokes, but will not watch it. I'd rather stay away from something like this then promote it.
Mighty Morphin Power Rangers - I could add nearly any action cartoon on my list. I didn't like them... is this even a cartoon? Not really.... but I didn't like it. I was too "mature" for my age to like this. Lol. I remember that was the saying back in my school-days. Kids at our school would base our maturity on the shows we watched and didn't watch, lol!
Aaahh!!! Real Monsters - I found this show to be very off-putting in it's character design and voices. It is an interesting concept for a show, but just not something that drew me in. I didn't find myself liking any of the characters so there was no interest in me continuing to watch it.
Teenage Mutant Ninja Turtles - Again, action cartoon... just not my cup of tea. I remember once ranting as a kid how much I deplored this show when it started and my Mom said to just turn off the tv and read a book. I did that! To prove my point how much I disliked the show, I pulled out a book and read in front of the tv instead! I think it was even a boring book too, like a dictionary.
Lol!
Rocket Power - I had a love-hate relationship with this show. I watched it every morning before school... but I never actually liked it much. I didn't like the main character, but I remember liking Raymundo and Tito. I remember they met Tony Hawk once too. I found the kids to all be kind of jerks, except poor Sam. They treated him poorly. Reggie X Sam tho.
Gargoyles - Didn't care for many Disney cartoons in the 90s, and I never liked this show. Character weren't that good to draw me in, nor the whole plot.
As Told by Ginger - Not only was this show ugly... but I just didn't understand it's purpose?! I must have been the wrong demographic. I never felt invested in the characters or their newest drama.
Hercules - I didn't like this show. I remember not liking it's design or finding the characters relatable.
Cow and Chicken - I really didn't like this show. I thought it was gross and the characters disgusting in how they looked and talked.
Scaredy Squirrel - His voice was so grating and annoying! I just didn't like this show at all. Animation was horrible.
Almost Naked Animals - Need I say more other then you seeing the name? I remember watching this atrocity. Horrible animation and horrible characters. Ugly show.
Fanboy and Chum Chum - ... I didn't like this show. I don't think many people liked it.
The Cramp Twins - I didn't get it. They didn't even look like twins. One was peach and the other blue! Why was he blue? Why the horrible animation, voices, and bad show name?
The Proud Family - I am torn on this show. I remember faulting it for it's bad animation at times and lazy writing, but at other times it was decent. I liked the character designs on most characters, but others I was questionable about. It was a show of highs and lows and some bad choices thrown in.
El Tigre - I thought this show had a creative design... but it was horrible in the type of animation they used. Often far too busy to even know what was happening. It's a shame, because it could have been good I think. But it was not a show I enjoyed overall.
That is my list for now. I am sure more will come to me.