My suggestion are
1: One piece a great journey of a teenager who wants to become the king of pirates and find the treasure called "One Piece" so he create his own crew and face strong pirates.
2: Attack on titan, basically an anime of titans who eat human beings, its been a long time since they ate humans but after they break the wall... many die and suffer.
3: Death Note is an anime about a teenager who found a death notebook where every name he writes get killed automatically, so he is going to write there a lot of criminals who deserve to die and he is enjoying by doing it.
4: Bleach is an anime about a teenager who can see ghosts, so after a big ghost appears and a mysterious girl cannot stop it, she gives him her powers of death angel and then he must protect the humans from the monsters ( Called Holous which are ghosts but are dangerous).
Recently, I'd been binge-watching some online series and anime. If you can suggest something new and appealing and where I can watch it, I will surely appreciate it. I love Japanese' animes but I would love to see the works of other countries too. Something with amazing graphics and unique story...