One show that still stands out to me for strong character development is Gurren Lagann. The interesting part about this show is Simon's development from a mere underground driller to a universal hero. You see him as a milquetoast in the first half of the show while being encouraged by his mentor Kamina, then when it hits ep8, he's tested by a great tragic loss that can either put him in the pits forever or move on. Of course, he overcomes that loss in ep11 which is probably my all time favorite anime episode and I get man tears every time I watch it. Everything about that episode is so well done; the lines, action, music placement, character interactions, etc. Simon becomes his own man by taking on leadership, delivering a Kamina class speech, performing the giga drill break all on his own, and doing the impossible possible (ROW ROW FIGHT THE POWAH! lol) when all odds are stacked against him. He surpasses his mentor on almost everything that makes him a symbol of hope for humanity's survival. Simon's growth as a character is truly inspiring.