May the fourth be with you--it's Star Wars Day! It's funny because I have actually been making my way again through the series on DVD (first the original trilogy; now I'm on to the prequels). My favorite would have to be Return of the Jedi. There are a lot of good lines in that movie, many of them said by the macho and sarcastic Han Solo. A few favorites:
Luke Skywalker: "Just relax and stick close to Chewy. I've taken care of everything."
Han Solo: "Oh. Great."
Luke: "Quiet, there may be more of them out there."
Han: "Hey. It's me."
C3PO: "They believe I'm some sort of god."
Han: "Well, why don't you use your divine influence and get us out of this?"
Princess Leia: "It only takes one to sound the alarm."
Han: "Then we'll do it real quiet-like."
The increasingly gleeful emperor when he has Luke in his clutches: "Oh, I'm afraid the deflector shield will be quite operational when your friends arrive." (This is a fun line to do an impression of!)
Of course, Star Wars also has a bunch of other things going for it: the epic storyline; great characters, including strong female leads (Padme Amidala and Princess Leia); the score; cool special effects; impressive costumes; and edge-of-your-seat battle scenes. It also touches on interesting philosophical points, which are often articulated by Jedi Master Yoda:
"Do or do not. There is no try."
"Fear leads to anger. Anger leads to hate. Hate leads to suffering."
"Attachment leads to jealousy. The shadow of greed that is."
"The fear of losing is a path to the dark side."