I would say that Pokemon, Power Rangers, and Kim Possible have elements that could be explored more "grittily." I'd also vote Batman and Samurai Jack but they were gritty to begin with.
In hindsight, while Pokemon and Kim Possible have touched on subjects so it'd be a narrative wise grittiness, Power Rangers is inherently goofy and I meant gritty designs, not stories. It'd be hard to make Rita Repulsa "srs."
