This is my favorite of the Trilogy. With the introduction of Yoda, Lando Calrissian, and the snow world of Hoth, it's amazing. The Empire seems so powerful and unbeatable. Darth Vader truly shows why he is the most feared bad guy of all movie history.
My favorite scene is the Millenium Falcon flying out of the spaceworm. It's so cool. The whole asteroid chase is so intense. It's just so fun and enjoyable. It causes a sense of awe and pleasure that few movies these days can bring to us. We've seen it all: dinosaurs, UFOs, and MiBs. We aren't just shown cool things, cool things happen and that is why Empire is so good.
The ending is such a downer and so real. The Rebels look defeated, the Empire is powerful. This is the best second part to a trilogy possible. It answers and brings new questions and that makes us all dying to see the third installment. I mean, who wasn't dying to see what Yoda had to say about Luke and Vader's relationship?
I love this film more than the other two, but it wouldn't be what it is without the other two. I give The Empire Strikes Back an A+.