How about something like this...

I, Phenom, am a big shot hollywood producer. Having stepped on any number of backs or jumped in the sack to get to the top it is time for my uppence to come! I have decided to throw a party to gloat over my success! It will be a Valentine's Day Party with the theme of Hollywood lovers and haters, on screen and off. Come as any character from TV or the silver screen from any time period.

*this allows you to come as you are or pretty much anyone you like, you decide your character in the game. Make it good! And it allows every to bring instruments of death! What was I thinking!*

Any other ideas?