Berserk

The way this story captivates is extremely immersive, intelligent, and well-planned.
With a slow start, Berserk unfolds spectacularly, showing character development like I've rarely seen and an exquisite story that touches on everything from the most political to the most personal.
Dialogues like Griffith's at the fountain, Casca's in the cave, and Guts's saying goodbye are some of the most human, believable, and well-written I've ever seen.
A spectacular soundtrack that gives you goosebumps, a fantastic medieval setting, a level of animation detail advanced for its time, and a level of action, violence, and rawness that would leave Elfen Lied or Hellsing in its infancy.
It's a unique story that, while it has few main characters—only three—develops them all spectacularly well.
It has one of the hardest, most unexpected, and most abrupt endings I've ever had the honor—or horror—of watching.
The way Guts leaves the gang, leading Griffith to act impulsively and then be imprisoned, is shocking because, for the first time in the story, the two protagonists swap roles: Guts, the impulsive and rabid uncle, becomes more human than ever, seeking to find his own path, while Griffith, the intelligent and calculating leader, commits such an unpredictable and desperate act in order to fulfill his ambition. In the end, Guts takes Griffith's role, becoming a respected and beloved leader, while Griffith loses everything: his strength, his leadership, his sanity, even his beauty. He loses everything except what defines him most, which is also his greatest flaw and, ironically, ended up being his most powerful weapon: his relentless ambition, which led him to unleash one of the harshest endings I've ever seen, the Eclipse. The Eclipse was, indisputably, what inspired Hideaki Anno shortly after to create The End of Eva̳ngelion, and what much later would inspire Isayama to create The Rumble, or at least to give it the form it had. The Eclipse is one of the most terrifying, raw and shocking endings I've ever seen, not only because of how visual and explicit it is, but because of the very idea of abandoning humanity in order to fulfill a selfish desire, the idea of crushing the dreams of others in order to fulfill your own is heartbreaking.
That's why Griffith is, in my opinion, one of the most complex characters I've ever seen. He's not a character you can pigeonhole as good or bad, but rather as inevitable. Throughout the series, Griffith is shown as Guts's counterpart: a handsome, intelligent, and calculating man, the spitting image of the Fallen Angel. He's an extremely complex character because he's a villain, but he's not evil. Griffith's motivations are good and noble, and even a man as cold as Guts fought alongside him to help him fulfill his dream. But it's his damned, relentless ambition that drives him to break the stereotypical idea of a villain with a tragic past. Griffith doesn't need a past, he doesn't need trauma; he only needs his ambition, his charisma, and his determination to achieve what he sets out to do, even if it led to the Eclipse, killing those who were once his companions, and savagely raping Casca to break Guts's spirit. Griffith is a character as complex as Johan Liebert or Shinji Ikari, and thinking that he's a character created in the 1980s is so hard to believe. It's impressive how many seinen anime have taken Berserk as a schoolteacher.
Berserk is a masterpiece that inspired many others, whose story starts slowly but develops and explodes as it should.
Rest in peace, sensei Kentaro Miura.