If anyone hasn't recommended it yet, then Vagabond. It's manga actually, there's no anime for Vagabond. But it's one of the best readings I've ever had. It's a character study pretty much, a character who wants to be the strongest under the heavens... But it delves in a philosophical quest and the development is amazing. Honestly, it's just too good and despite not having an official ending, I feel where Inoue finished writing is already satisfiable enough of an advancement we've had for the story.