I am really fan of One Piece.
Charecters are just brilliant (specially Strawhat crew members)
Storytelling is epic (Each Arc grows to brilliance at end with suprises)
Adventure feeling (Huge sea with adventures and each island arc is just awesome (manga) )
History (Where did World govermet came? What and who was civilization what they destroyed? What happened during Lost History? What and where did Devil fruits came? What are super weapons of ancient times? Why World Goverment is ready to annihilate entire countrys to prevent even hint of Lost History to be revealed?)
Humour (it's just awesome
all strawhats can be just silly )