There is manga and anime which makes me want to go out and fix everything wrong with the world. I quickly lose motivation but they are still great and defines how to be a man.

Hokuto no Ken: Some guy is a master martial artist assassin and he goes around kung-fuing people to death. He fights other martial artists and is not afraid to cry like a real man. Silently with a stream of tears down his face. Many other anime mimic or reference Hokuto no Ken when they need something manly.

Gintama: Men love sweets and its a proven fact. This manga talks about the secrets between life and how sweets tie in to everything related with life.

Vinland Saga: This is a manga about vikings. Everyone knows that vikings are the manliest thing besides dinosaurs to walk the earth.

GTO: A teacher teaches his class and fellow teachers how to be a man. He falls off a school building multiple times and survives. He also revives from the death through sheer willpower to save someone from a burning building.

Magical Girl Lyrical Nanoha: A girl gains magical powers and befriends people by blowing them up.