Vagabond by Takehito Inoue - a Samurai (a genre I love, thanks to Kurosawa) manga about the swordsman Miyomito Musashi (a real life historical character), in fact, I accidentally happened to read Miyomito's strategic book (like sun tzu types) The Book of Five Rings, and I'm just loving the experience.
Gangsta by Koshke. As the name suggests, it is an urban crime and mafia drama that digs deep and runs layered,
I often get back to rereading those Manga where I started. I developed interest in classical literature of Shakespeare's through Manga. I'm reading the Emma Vieceli and Richard Appignanesi version of Hamlet manga. One of those plays that I loved and keep applying in daily life, the concept of honor and revenge.
My Hero Academia by Horikoshi. An excellent super hero Manga series.