City of Heroes / City of Villiains May not seem like and obvious choice but to me it screams Halloween. One of the best parts of the game was the Hero Creator, you could make just about anything, and to this day it's the only MMO I played where I felt like a unique individual. Most MMO's you run around and you always see someone who looks similar but the Hero Creator for this game was so amazing that I lost countless hours not playing the game but designing costumes, heroes, and villians. This Hero Creator was like the worlds best costume shop and always made me feel that Halloween joy. While this would be enough to earn it a spot on the list, City of Heroes also had really great Halloween events. I didn't matter if I hadn't palyed in month, when the Halloween patch went live I was logging in. I miss this game.