One Piece is another series that seems to have been airing forever. Luffy and his pirate friends have maintained a TV presence for almost fifteen years, with no real end to their escapades in sight. Over time, the series has had the opportunity to introduce countless characters and develop them as well as weave a compelling, engaging story that keeps viewers coming back hundreds of episodes later.
15. Detective Conan (Case Closed) with 802+ Episodes
FUNimation released the first 104 episodes of this mystery-of-the-week series about a genius detective trapped in the body of a child, while Crunchyroll’s been streaming it since episode 754. As the popularity of this classic anime doesn’t seem to be cooling off any time soon, Conan will surely make its way up this list of the longest running anime in the future, so please stay tuned!