Out of curiosity, what is your ranking from favourite to least? Having a sense of what you value in a Star Wars film might help illuminate what you feel is lacking in ESB.
MY top 2 are RotS and ANH, that I both love for different reasons (one’s emotional, the other’s lighthearted fun). After that it’s kind of ambiguous. While RotJ is by no means the worst, it’s the one movie whose mistakes actively offend me (second Death Star, Leia Skywalker). By comparison, my least favorite is AotC, which is bad simply by virtue of being boring. But hey, at least the worldbuilding’s good. I never cared for Han and Leia’s relationship. I can see how that would hamper my enjoyment of ESB.
Maybe I should just explain my tastes in general, outside of SW. I tend to gravitate towards more “kiddy” stuff a lot of the time, favoring shows like Code Lyoko and Mystery Incorporated to mainstream stuff like Breaking Bad or The Walking Dead. I’m a huge fan of Doctor Who (currently on classic season 3). I think the Harry Potter movies got progressively worse, with the Columbus ones being amazing and the Yates ones being practically unwatchable. I usually only watch fantasy (and by that I mean anything contain non-realistic elements not presented scientifically). I like trains.