The Entire Cast in Inception
Inception is fantastic for so many reasons. The entire plot of the film was thought out and purposefully done, even the costumes of the characters. Of course, with so much going on, a lot of the audience didn't quite catch on to the secret messages that each character's outfit was supposed to portray, so some critics felt that it was an oversight. Of course, if you watch the movie 10 times, you'll start to notice more and more purposeful things.
Princess Leia in Return of the Jedi
The fiercely independent Princess Leia had to put on a golden bikini when she was Jabba the Hutt's prisoner. Many feminists at the time felt that this was demeaning, while others tried to say that it was the point of the entire scene. George Lucas himself later came out to say that it was chosen off of aesthetics...