There's at least 8 shows with similar designs. Though to be more specific it looks a lot like Steven Universe and OK K.O. Very rounded and pudgy characters, bean-shaped mouths ect. Maybe it's because I loathe this particular style, but there's not enough variation for me.
At least Gumball has mixed media going for it to make it interesting visually.
I agree with most of this. Though in terms of writing nothing's gotten near Avatar, Spectacular Spider-Man and Young Justice for me in a good 6 years or so.
Visually, Ultimate Spider-Man I actually enjoyed, I liked the subtle change to Peter's design as the show went on and he got older,(he got a bit buffer, and his jaw is more squarish)
2012 TMNT and Transformers Prime are contenders though, both in visuals and story.