Empire Strikes Back (ESB) is befittingly considered the greatest of the Star Wars films. While not this troper's favorite, it is still a truly great film.
THE GOOD: Almost everything. The music is iconic and perfectly sets the tone for each scene. The asteroid chase in particular has exciting music that draws you right into the action. The cinematography by Peter Suschitzky deserves special mention — the lighting of the film is gorgeous. In terms of Luke's story arc, ESB really does a lot to flesh him out from the inexperienced farm boy we see in ANH. Here, we see him in a transitory phase as a young commander in the Rebellion. He's learned how to be a leader, but struggles with impatience and impulsivity. His love for Han and Leia really shines through as does his trust in Obi-Wan (which becomes rather heartbreaking by the end of the film). Yoda's instruction is among the best scenes of the Saga as you can really see Yoda's terrible sadness over what has been lost and caution due to how readily he realizes everything could go wrong. On the Imperial's side, the officers are surprisingly compelling — both Needa and Piett (bit players) are not wholly evil and seem to have some integrity. Giving them a human face adds dimension to the conflict and a touch of moral ambiguity which is well-incorporated given the famous plot twist at the ending of the film.
The Bad: There's not much plot, unfortunately. The other Star Wars films all have a larger, overarching plot along with more intimate character pieces that is lacking here. The Empire attacks in the beginning, but nothing really seems to change for either side. The focus is largely on Luke's development. The lack of a compelling Rebellion vs Empire conflict is a bit frustrating. That and some of C 3 PO
's remarks at the end of the film can be tonally jarring.
the ugly: Han and Leia's romance. Quite honestly, it could have done without the "yes means no" vibe. Han's complete lack of respect for Leia's protests always made this troper uncomfortable. Even if Leia does like him, it's not Han's place to force physical contact. Fortunately it improves in ROTJ but as it stands, this troper finds it remarkably out of character for Leia to respond to Han's "advances" the way she does.
Overall, a wonderful, sweeping adventure with a few minor flaws (and one big one).