Costume party dilemma, what to wear...?

A friend of mine is throwing a party this weekend at his house and has required everyone in attendance to show up in a costume of their choosing. Being a girl, I was urged by friends to go as something slutty, but I honestly feel that would be too generic (and frankly, I don't think I'd be very comfortable as I'm quite skinny and lack in the boob region ha). I've unfortunately had to nix the idea of going as a girl version of Han Solo due to the fact that no one would recognize it, and so I've narrowed it down to two choices: Emma Stone's Easy A character, and a member of the Navy Seal Team Six- complete with bloodied Osama Bin Laden mask in hand. I thought both would be witty and while I have all the materials for the former, I feel as though going through the trouble to find the Osama mask and a wetsuit would really be a hit amongst my fellow college aged buddies (most of them guys). Are either of these worth it to go as? If not, any other suggestions are much appreciated. Thanks.