Vagabond.

Vagabond is no joke. It's the highest echelon of manga, or storytelling in general. As far as I'm concerned, there's no equal to it in the medium of manga. It's a special thing. EMBRACE IT.

Vagabond is a fictional account of the life of the legendary swordsman Miyamoto Musashi, which is in turn based off of the novel Musashi, which is also a fictional retelling of said legendary swordsman. Musashi's life is told fantastically through some of the best artwork and dialogue I've seen in a manga. Nothing here is wasted. There aren't any stupid cliffhangers. Each battle is a philosophical experience, with Musashi reaching new heights of understanding as he defeats each challenge laid out before him. It's inspirational to read. If you do nothing else in your pitiful life, read Vagabond.