Group of 6- HELP!! We need Halloween Costumes!!?

So this Halloween my 5 friends and I are going to go tricker-treating together. We live in a very small town so we can go to pretty much every house. We have one problem though.... we don't know where to get our costumes or what kind of costumes to get. We want to get costumes that all corispond to each other. Like all marvel characters or something. There are three girls and three guys. Also, we are 12-13 years old. We where thinking of going as the Scooby Doo Gang, but thats only 5. Or having everyone dress up as the Spice Girls, but its still only 5. We would like something movie, tv, or music related. THANK YOU!