Of the three, I still think that the original '77 is the best. In fact, I always considered TESB as a much weaker movie, and largely still do. SW is almost a perfect movie, with a great pacing and cohesion, and every scene being important to the plot development. By contrast, TESB to me always seemed like a series of imaginative scenes, rather than a single movie, and some of the scenes are largely irrelevant - the asteroid cave scene to me always seemed silly and extremely unrealistic (gravity, for starters). However, it has two very strong elements - (1) Yoda and the deeper exploration of the spiritual elements, and (2) the climactic scene when Vader puts Han in the freezer. The timing in the latter is really excellent, and everyone’s acting (particularly Carrie and Harrison’s) is top notch. It’s also surprisingly realistic - pretty much how a cruel tyrant and an arrogant victim would likely interact. Vader wastes no time (unlike the emperor in ROTJ where the interaction drags on and becomes unbelievable). So lately I have come to appreciate TESB much more than I did when I was younger. But SW is still my favorite.