The most underrated Star Wars animated series is Star Wars Rebels. However, it can also be the most difficult to figure out. Star Wars has had a habit of jumping across the timeline with its various projects (and sometimes within them) and Rebels is no different. That makes it hard for viewers to pinpoint exactly when in canon the events of the series happen.
Source:https://www.cbr.com/star-wars-rebels-seasons-franchise-timeline/