Wanpaku Ouji no Orochi Taiji

Wanpaku Ouji no Orochi Taiji is a very stylised cartoonish adventure version of the heroic cycles of japanese mythology. Ousama Ranking in the same way is a hero's journey told in this very stylised art style with the world building very inspired by old fairy tales and medieval european folklore 

Both are family-friendy coming-of-age stories about a young boy who loses his mother early on and goes on an epic journey through a variety of locations. Both have great main characters as well. Wanpaku Ouji is older but has smooth animation, an amazing sound mix, and some great action. GE999 is more story and character driven with some philosophizing. 

I remember that I found wanpaku ouji through hols. these are both older shows and are about prince like boys who are strong and fight for JUSTICE!