In a sense, true, that western animation tends to humour-ise the stories...
But if you're talking about creative options, I'd say the most creative animes are the ones least heard of..! Or least discussed..
Ghost In The Shell (1995), Akira, Animatrix are pretty damn creative....all of them showcasing grim forecasts for the future of man..
Nausicaa, Howl's Moving Castle, and some other Miyazaki works are impressive for the detail that was put into the world.
Among manga I found White Clouds (one-shot) to be beautiful. A not-so-heard-of manga Cage of Eden (shonen with bits of ecchi) is another great read (million year old dinosaurs eating people...so common and boring nowadays. But what if we replaced the dinosaurs with million year old mammals? Throw a bunch of kids into the pot and we have a gem!)..
I also remember Gundam as a must-watch from when I was a kid..also there was an anime called Brain Powerd, and I loved the concept..
And many more like Baccano!, xxxHolic, Honey and Clover, Cowboy Bebop...
http://timmaughanbooks.com/2009/04/25/ten-anime-films-you-should-see-before-you-die/ <--check out this guy's list of anime films...
Among cartoons, the one I found to be hilarious and meaningful at the same time was Spongebob Squarepants!!!
Whadya think??