The debate that never ends. For each major series, I am going to tell you which version is the definitive experience and why.
Manga is definitively better:
- One Piece — Toei Animation's pacing is criminal. A single manga chapter gets stretched into 18 minutes of padding. The manga art by Oda is expressive and detailed. Read the manga, use the anime for key moments only. Alternative: One Pace fan edit.
- Berserk — Kentaro Miura's art in the manga is the most detailed and beautiful in the medium's history. No anime adaptation has come close to capturing it. The 1997 anime is decent but covers only the Golden Age arc. The 2016 CGI adaptation is an insult.
- Tokyo Ghoul — Studio Pierrot butchered the adaptation. The manga by Sui Ishida is a gothic tragedy. The anime is an incoherent mess after Season 1.
Anime is definitively better:
- Demon Slayer — Koyoharu Gotouge's manga art is serviceable but Ufotable's animation elevates every fight to cinematic quality. The Hinokami Kagura sequence in Episode 19 of Season 1 transcends the source material.
- Mob Psycho 100 — ONE's manga art is intentionally crude. Studio Bones turned it into one of the most visually creative anime ever. The animation adds emotional weight that the manga hints at.
- Attack on Titan — Hajime Isayama's art improved over the run but MAPPA and WIT Studio's adaptation of key moments (Levi vs. Beast Titan, the Rumbling) adds sound, music, and movement that the manga cannot replicate.
Both are excellent:
- Fullmetal Alchemist: Brotherhood — Hiromu Arakawa's manga is great. The Brotherhood anime is a faithful adaptation with excellent voice acting and music. Either works.
- Jujutsu Kaisen — Gege Akutami's manga art is dynamic. MAPPA's animation is spectacular. Both are worth experiencing.
- Chainsaw Man — Tatsuki Fujimoto's manga has legendary paneling. MAPPA's anime nailed the tone. Read the manga for Part 2 content the anime has not reached.
Sources: Publisher sales data, MyAnimeList/MAL ratings for both versions, studio credits
Attack on Titan's "Ashes on the Fire" playing during the Rumbling sequence in the anime adds a layer of horror and grandeur that reading the manga panels cannot replicate. Music matters.