Note of Discord said:
The Mysterious Cities of Gold; greatest children's cartoon ever made.
...although from the looks of things you youngsters probably won't remember it.
I was about to post saying "I'm shocked and incensed that no-one has mentioned this", and so am glad I hit refresh before posting.
Can't argue with a show that started with the plotline of a cult classic novel, quickly went off the rails and introduced half-aliens with a penchant for world domination, scads of solar-powered tech, topless inca statues, nude bathing, instructions on how to make grenades out of plant pots and goat manure, a sentient parrot, the occasional acid trip, had actual educational segments tacked on that were far better than anything He-Man ever attempted, and featured one of the era's most singable theme tunes in an era of pretty good theme tunes (heck, an era of actual intro and outro sequences, that you didn't get so much before or since) - to the point of a kids' TV presenter starting a nationwide sing-a-long in response to several request letters. Which was made by a studio featuring several former Miyazaki collaborators, and became the stuff of cult legend for the best part of 20 years after disappearing from TV as suddenly and mysteriously as the titular cities before finally resurfacing on DVD (and has seen two failed reboots to date - maybe it is actually cursed?)
+10 internets to you, good sir/madam.
Also Dangermouse, Count Duckula, Trap Door, Dogtanian, Bertha, Inspector Gadget, Willy Fogg, Thomas the Tank Engine,
Hero Turtles (bite me I'm British), Real Ghostbusters, Bravestarr, Defenders of the Earth and all that lot. Christ, looking at the copyright dates makes me feel old.
There was a hell of a pile of good stuff in the 90s too, but I think that's going to be more comprehensively covered by the younger contingent if it hasn't already.