Sorry, Hillenburg was sort of implied in my response.
Antonucci, McHale, Osborne, Nick Park, Tomm Moore and maybe Man of Action. I would have Del Toro as an honourable mention.
Man of Action is something I thought about, but since it wasn’t a specific creator, it gets hard to say. I do agree though. I was never much of a Ben 10 fan, but Generator Rex is low key one of the best action cartoons ever made and a great horror at times. If I am not mistaken, did they also do Jackie Chan and The Batman?
Antonucci is another great given Ed, Edd n’ Eddy.
For Nick, like Man of Action, you could probably just say Aardman in general as other than Selick and Burton they are the stop motion people.
The rest I am less familiar with, but they all look good. Hell I didn’t even know about McHale even though I found Garden Wall fantastic.
What about John k and Ralph bakshi?
Not so familar with Bakshi, but I know his influence is big in theatrical adult animation.
As for John, ehhh…. He is hard to want to put on a list as he only developed like 6 episodes of Ren & Stimpy before being fired for his abusive shit. After that, pretty much all his works downgraded in quality. He was sort of a one-hit-wonder that barely held influence on most of that one hit. Plus again, giving credit to a massive abuser, pedophile, and man that wrote multiple hit pieces on animation is hard to justify. This is sort of why I also left out Butchy boy even though his creations, Fairly Odd Parents and Danny Phantom, were massive hits. It is questionable how much he really did for those things, along with him being a crazy ass.
Also, should add DNA Productions to the list if we are adding small studios. They were the first animation studio to build a CGI movie off publicly-accessible tools and Jimmy Neutron was easily the highest quality CGI series of its time given it used movie models. Jimmy also had continuity in a comedy series, something that took off more a decade past it. Enter was probably right in saying that Jimmy walked so that Nick would take the risk and allow Avatar to run.
Also, should we add Avatar’s creators to the list?