I'll stick with the safe bet and say Return of the Jedi, but damn if Rogue One isn't nipping at its heels. Saw the movie today, will see it again on Sunday, so will see if the sheer sensation of it is the same.
Visually, each film is at a respective height for the style of effects that it uses, particularly for the space battles. Return of the Jedi has what, for me, can only be described as a tapestry of modelwork up on screen, with immense pace and scale. Rogue One's Battle of Scarif, while avoiding too many spoilers, is just gorgeous to look at while being able to benefit from much more specific choreography and framing, owing to the digital arena - in contrast, you do notice a little in Return of the Jedi how things aren't really interacting with each other because of how they were made separately.
What bolsters the both of them is how these epic space battles are connected with the battles on the ground. It creates a greater sense of cohesion between seemingly separate sequences, so there's ultimately still a progressing, singular story. What edges it for Jedi is of course the Vader and Luke stuff on top of that, in part because of just how disconnected it is. Nothing those two do in that throne room will alter the course of the battle, and so it's able to focus on the culmination of the arc established at the end of Empire Strikes Back. It's ground battle may not be as strong as Rogue One's, but that little extra puts it in front. For now.