One such manga is 'Magi: The Labyrinth of Magic'. Despite its huge fan base, it still awaits an anime adaptation. Maybe it's due to various production and licensing issues.
Well, 'One Piece' could be a great choice. Its long and complex storyline, filled with adventure and unique islands, would make for an epic anime. Plus, the characters are so beloved that an adaptation would likely draw in a massive audience.
I believe 'Hunter x Hunter' is a shounen manga that deserves an anime. It has complex characters and a rich story that would translate well to the screen. The themes of friendship and adventure would appeal to a wide audience.
'Bleach' was a popular manga in Shounen Jump but didn't have an anime for some of its later arcs. Maybe that counts. But it did have an anime for the earlier parts.
One could argue that 'Naruto' has a highly successful anime adaptation. It gained a massive fan following and stayed true to the manga's core elements.
For me, 'Doukyuusei' has a wonderful anime version. It stays true to the manga's charm and adds some nice visual touches. The character development is also well-portrayed.
For me, 'Blue Lock' has an excellent anime adaptation. The visuals are stunning, and it does justice to the complex story and characters from the manga. Some minor changes were made, but they added to the overall experience.
I think 'Given' has a quite popular anime adaptation. The story and characters are loved by many.
I'd say 'Naruto' has a relatively loyal adaptation. The anime captures the essence of the manga well, with only minor tweaks here and there to make it suitable for the animation format. The key moments and character arcs are presented accurately.
My pick would be Dragon Ball. The anime adaptation of this manga is legendary. It has become a cultural phenomenon and is still loved by many. The fighting sequences and the story's progression were done exceptionally well.
It's decent. The anime version of Kindaichi Shounen no Jikenbo stays relatively close to the manga, but there are a few differences.