I’ve never heard of Osamu Tezuka’s The Wonder 3 (aka The Amazing 3) before, but it seems to be one of the better animated series to come out of Japan in the 1960s. The animation and character design are more sophisticated, the characters have more depth to them, the storytelling is entertaining and crisp, and there’s even a few moral dilemmas (for example, when the aliens consider blowing up the Earth to end humanity’s violent ways, The Wonder 3 note that this solution is also violent).