This year I decided to go as a 1990s laser portrait of myself.
I had originally toyed with the idea of wearing a vest and carrying a bag of combs and my camera and saying I was a school portrait photographer for Halloween, but then it occurred to me to flip the idea and be the portrait instead. The internet being what it is, someone had of course already had this idea at some point, because I was able to very easily find a perfect high-res laser background to suit my needs.
I strongly endorse this costume, should any of you wish to try it at some point. You get to wear a great '90s outfit and look super cheesy in every picture. As a bonus, people will point at you all night and say things like, "OH MAN! MY MOM WOULD NEVER PAY THE EXTRA $10 FOR THAT DAMN BACKGROUND!" And then you can hand them your posterboard and make up for the portrait they were never allowed to get as a kid.