I am having a 17th party and i need to pick a theme i want something that hasent been done befor ?

i am having a 17th birthday party and its going to be big i wnat a really good theme that everyone can dress up and look there best but i dont want somethign that has been done befor lik fluro and pimps and hoes i want something origional and funnnn :) i want to have the best party