Which anime series has the most faithful manga adaptation?

In my opinion, Naruto has a pretty close adaptation. The characters, storylines, and major events are mostly consistent between the manga and the anime. Some minor details might be different, but the core remains the same.

I think 'One Piece' has an anime that is mostly true to the manga. It follows the adventures and character growth precisely. There might be some filler episodes, but the main storyline remains consistent with the manga.

I'd say Naruto. The anime sticks closely to the manga, keeping the core story and character developments intact.

One such anime is 'Fullmetal Alchemist: Brotherhood'. It's widely regarded as having a very close adaptation to the manga, maintaining the core plot and character developments.

I think One Piece has a very loyal manga adaptation. The anime captures the essence and major plot points well.

I think 'Fullmetal Alchemist: Brotherhood' has a very faithful adaptation. It closely follows the manga plot without major deviations.

I think One Piece has a very faithful adaptation. It captures the essence and major plot points of the manga quite accurately.

In my opinion, 'Sword Art Online' has a pretty close manga adaptation. It manages to capture the key elements and action scenes well. However, there might be a few minor tweaks to make it more suitable for animation.

'Attack on Titan' is another example. The anime mostly follows the manga precisely, with only minor changes to fit the animation format. The core story and character arcs remain intact.

I think 'Fullmetal Alchemist: Brotherhood' has an extremely faithful adaptation. It sticks closely to the manga's story beats, character arcs, and themes. The few changes made are mostly to enhance the visual and narrative presentation and don't stray far from the original manga.