Amazon Prime Video may feature a lot of original movies, but it's also got one of the deepest film libraries among the major streamers. Among the new movies in September, the latest additions span decades of cinematic history. Watch With Us has narrowed down this month's arrivals to the three new Prime Video movies you need to watch in September. Our picks for the month include a hauntingly romantic film celebrating its 45th anniversary this year, as well as a seminal action flick and an underrated dystopian story. 7 Must-Watch Drama Movies on Prime Video (September 2025): 'Chef' and More 3.