This debate has raged for 20+ years. I am going to settle it with actual citations instead of nostalgia.
One Piece (Eiichiro Oda, 1997-present, 1100+ episodes)
- The worldbuilding is unmatched in any medium. The Void Century mystery, the Will of D., the political structure of the World Government — Oda planted seeds in Chapter 1 that paid off 1000 chapters later.
- Best arcs: Water 7/Enies Lobby (Episodes 229-312), Marineford (Episodes 457-489), Wano Country (Episodes 890-1085). Each of these arcs has emotional depth, complex villains, and stakes that feel earned.
- Weaknesses: The pacing in the anime is brutal. Toei Animation pads episodes with 5-minute recaps and slow reaction shots. The manga is the superior experience.
- Sales: 530+ million copies worldwide. Best-selling manga in history. Source: Shueisha official sales data.
Naruto (Masashi Kishimoto, 1999-2017, 720 episodes across Naruto/Shippuden)
- The ninja combat system is the most creative power system in shonen. Jutsu classifications, chakra natures, and the Sharingan evolution create tactical depth that other series lack.
- Best arcs: Chunin Exams (Episodes 20-67), Pain's Assault (Shippuden Episodes 152-175), Itachi's Truth (Shippuden Episodes 135-141). The Pain fight is peak anime.
- Weaknesses: The Fourth Great Ninja War arc (Shippuden Episodes 261-479) is too long and introduces power scaling that breaks the established system. Kaguya as a final villain was a mistake.
- Filler: 40% of the anime is filler. Source: Anime Filler List. This is indefensible.
Dragon Ball (Akira Toriyama, 1984-present across series, 500+ episodes)
- Created the template every shonen series follows. Without Dragon Ball, neither One Piece nor Naruto exist.
- Best arcs: Frieza Saga (DBZ Episodes 75-107), Cell Saga (DBZ Episodes 166-194). Goku going Super Saiyan against Frieza is the most iconic transformation in anime history.
- Weaknesses: Dragon Ball Super's Tournament of Power relied too heavily on nostalgia. The power scaling has been meaningless since the Buu Saga.
The verdict: One Piece > Naruto > Dragon Ball for overall quality. Dragon Ball > both for cultural impact and historical importance. Naruto has the best individual moments.
Sources: Shueisha, Viz Media, MyAnimeList ratings, Anime Filler List