The original and prequel trilogies are worthwhile viewing. The sequel trilogy, however, presents a different case. While George Lucas provided story treatments during the 2012 sale, these were ultimately discarded. The sequels also marked the end of the Expanded Universe, removed from canon to allow creative freedom for filmmakers. Given that the stories deviate significantly from Lucas’s original vision, is there really a compelling reason to watch them?
I’d argue you should watch A New Hope because it was groundbreaking at the time, Empire Strikes Back because it’s amazing by any standard, and Return of the Jedi only if you crave resolution. Then watch Rogue One because it’s borderline better than Empire Strikes Back.
There’s only 2 good Star Wars movies that are good by the standards of modern cinema.