My ranking isn’t meant to be objective, as if that were even possible.
My fifteen year old self really enjoyed ROTS in the theater a few times and there was enough there in terms of philosophy and ideas at play. Even when Star Wars isn’t doing so hot in terms of the actual movie, there’s usually still some good ideas to chew on and extrapolate from. Anakin’s psyche, the nature of power corrupting good intentions, desperation, idealism, etc. Even if it’s hokey, it’s the archetypal content that undergirds Star Wars. The execution of the prequels was fucked, but ROTS had that key ingredient poking through.
I enjoyed the saber duel between Anakin and Obi-Wan, as well as a masked Vader asking whether Padme was safe, turning Vader into a tragic figure to pave the way for my beloved ROTJ and his redemption.
The Last Jedi made me feel like an idiot, and I think it was on purpose whereas the prequels did the same by incompetence.
I’m just reporting my personal experience, and your mileage may vary.