Attack on Titan

Several hundred years ago, humans were nearly exterminated by titans. Titans are typically several stories tall, seem to have no intelligence, devour human beings and, worst of all, seem to do it for the pleasure rather than as a food source. A small percentage of humanity survived by walling themselves in a city protected by extremely high walls, even taller than the biggest of titans. Flash forward to the present and the city has not seen a titan in over 100 years. Teenage boy Eren and his foster sister Mikasa witness something horrific as the city walls are destroyed by a colossal titan that appears out of thin air. As the smaller titans flood the city, the two kids watch in horror as their mother is eaten alive. Eren vows that he will murder every single titan and take revenge for all of mankind. (Source: MangaHelpers)

Tokyo Ghoul

The suspense horror/dark fantasy story is set in Tokyo, which is haunted by mysterious "ghouls" who are devouring humans. People are gripped by the fear of these ghouls whose identities are masked in mystery. An ordinary college student named Kaneki encounters Rize, a girl who is an avid reader like him, at the café he frequents. Little does he realize that his fate will change overnight. (Source: Anime News Network)

Sword Art Online: Alicization

Kirito awakens in a vast, fantastical forest filled with towering trees. In his search for clues to the truth of his surroundings, he encounters a young boy who seems to know him. He ought to be a simple NPC, but the depth of his emotions seem no different than a human. As they search for the boy's parents, Kirito finds a peculiar memory returning to him. A memory from his own childhood, of this boy and a girl, too, with golden hair, and a name he should have never forgotten - Alice. (Source: Yen Press) Note: The first episode aired with a runtime of ~48 minutes as opposed to the standard 24 minute long episode.</i>