Mighty Max. Anyone remember that cartoon? In my opinion it was one of the most "adult" kids' cartoons of the 90s. Not adult in that it had a lot of sex and swearing, but adult in that it didn't treat the viewer like a child. The show had an incredible amount of gravitas in that when characters died in it, they were actually dead, not knocked out or anything like you'd normally get in a kids' cartoon. As a child this helped teach me about the value of human life and most especially how a true hero is willing to sacrifice himself for the greater good, no matter what the cost. This is best exemplified when Max meets a bunch of famous mythological heroes who all die to ensure that he completes his quest, and of course in the final episode when the (spoiler alert) same thing happens with two of the main characters.
On top of that the show had a limitless potential for storytelling thanks to Max's "cap," which opened portals to anywhere on Earth, outer space or even cyberspace. Max fought off everything from brain-sucking aliens to monstrous gothic horrors to mutant dinosaurs to the chief antagonist (voiced by the ever awesome Tim Curry) Skullmaster. When one of the first things the villain in kids TV series says on seeing the protagonist is "I want to eat his heart beating raw" you know that "kids" show has balls. Seriously, if you haven't seen this show before check it out.