Sometimes, an anime just needs a solid revamp, and the best anime reboots stand as a testament to the power of re-imagining a beloved series. This practice, where an old anime gets reworked with modern animation and fresh ideas, injects new life into a series either forgotten by time or without a proper conclusion. Some of the best anime remakes introduce anime fans to history they might otherwise have ignored. That's what happened to Devilman, a '70s anime remade in the form of Devilman Crybaby, which updated the art and style and introduced new fans to the series.
Another reason a studio may remake an anime is to more closely follow the manga source material. The 2003 version of Fullmetal Alchemist boasts plenty of its own merits, but it largely veers off course from Hiromu Arakawa's story in the manga. For fans of the manga, the 2009 remake, Fullmetal Alchemist: Brotherhood, is a welcome addition to the anime canon, even ranking as one of the best anime of all time.
Not every anime that deserves a reboot receives one, and some reboots even end up eliminating the joy of the original series. That said, the anime below not only rebooted their series faithfully, they did so in ways that improved upon the existing property. This doesn't necessarily mean that the original series is bad – instead, it means the reboot adds something new, and provides a worthy viewing experience all its own.