Halloween is next weekend. You still have time to get a costume other than the Joker. Seriously. The only way you can redeem that one is to play Rock Band with three of the other seven Jokers at the Halloween party.
You could take that idea and turn it into something interesting. The Crow comes to mind, and you need two more dead celebrity superheroes. Then you can make a theme of it. Adding the Rock Band instruments can only help.