Anonymous
The one where Vader has sex with teenage sluts from planet Voodooppodoo.
Anonymous
One of the first three movies that were being made; IV, V, VI. They are all about equal.
u_bin_called
To me, it's still the original 1977 "Star Wars"...which later became "Episode IV"...
It is still the most pure and complete, with strong characters, a thrilling plot and good balance between action and dialogue. The rest of them all seem like installments in a weekly TV series to me. "Star Wars" remains a standalone "epic" in it's own right.
Mr Monster
The Empire Strikes Back
Entropy
Empire. It's always going to be Empire Strikes Back if you ask 'best'. A New Hope was arguably more ENJOYABLE, but Empire was the best movie of the series by a fairly large margin. And there's a reason - it's the one of the original trilogy that Lucas didn't direct.
Lucas has strengths and weaknesses as a creative force, and they're both on display in ANH. ESB bring his strengths with general plot direction, technology, the visual language of film, editing, and such...but doesn't have as much of his weaknesses with dialogue and actual direction. Kasdan did a MUCH better job with that.