Zoro

Because we all know that the ladies are always interested in a mysterious man, Zoro is a great and easy costume to put together. (Note, this costume isn't strictly for guys. This would look great on a lady)

Required clothing:

-Black Dress shirt
-Black pants
-Black Shoes
-A the oh so important black mask(can easily be made with just a little bit of black fabric cut in a narrow strip with two eye holes.)
-A Black cape
-For added effect a sword is good

A sexy accent and smooth demeanor also helps out the costume (and your popularity).