The costumes in the Egyptian/Arabian category are a great choice for a multitude of reasons. These costumes are recognizable as they have been shown in popular culture for years. Everything from "I Dream of Jeanie" to Cleopatra. These costumes are popular and are a great choice for a costume party.
Cleopatra costumes are very popular no matter what year it is. Its the night for royalty when you're wearing a Cleopatra costume. Command respect, and get those who are beneath you to do your will. You're royalty, and they should respect you.
Another option is to be Princess Jasmine from "Aladdin". Look like you stepped out of the Arabian Nights Tale. Or, step out in a harem girl costume. Dazzle party goers with brightly colored harem clothing. Choose to be a modest version, or ultra sexy.