Halloween. During my lifetime, the celebration has grown from school and after-school parties plus trick-or-treat into a month-long season of decorations and activities for all ages.
Little kids in cute costumes. Older children running down the street high on sugar and good fun. Adults hosting parties with food disguised as classic horror movie items. Midnight (or earlier) showings of scary movies.
A lot of time, money, and effort goes into some of the displays. I rather enjoyed this interpretation done a few years ago at the St. Louis Zoo.