Horror movies may tend to congregate in the fall around October, but scary flicks are always in season. This week, I Know What You Did Last Summer is reviving the classic horror franchise with a sequel that doubles as a remake. It's too soon to say how that flick will compare with the best summer horror movies as ranked by Rotten Tomatoes score. But since the Watch With Us team has put this list together, we can tell you that the original I Know What You Did Last Summer didn't come close to reaching No. 1. 3 Must-Watch Horror Movies You Need to Stream in July 2025 5.