The one date that has never let me down is October 31st.
I enjoy the day too. I also play Guild Wars 2 which has a special event call Shadow of the Mad King. It is Halloween themed and the main city is decorated for the event. Has a great fun dungeon where you get 20 or so people running around killing giant candy canes, skeletons, and other Halloween creatures. Lots of fun.
Best holiday of the year. Giving with no expectations. Dressing up. What is not to love?