I typically don't figure out my costume until the day before Halloween, and then I go on a massive last-minute shopping spree to get everything together. I still have no idea what I'm going to be this year, but here are some pictures from years past (pay no attention to the drunkenness in our eyes!)...
My roommate and I as Mal and Jayne:
The same roommate and I as Jim Halpert (The Office) and Chuck Bartowski (Chuck):
Peter Parker --> Spiderman --> Venom
(yes, the Spiderman and Venom costumes were actually toddler pajamas):
And, of course, my roommate and I as He-Man and Prince Adam:
For two straight guys, we have had some pretty gay costumes.