Sell your pumpkin heads! Team Fortress 2's [official site] Halloween event has launched. Scream Fortress runs from now through till November 11th, comes with a new comic, and introduces themed items, maps, taunts and an event that lets you win items from all previous Halloween events - presumably tanking the market for them in the process.
Every player should now have a Scream Fortress Gargoyle in their inventory that lets them "summon the dark spirit of Merasmus from the inky depths of Sergei's trunk." In translation, it lets you play any of Team Fortress's previous Halloween modes and potentially win the items that have previously been exclusive to those events. You can also unlock the new Gargoyle Case this way, which contains 19 new community-made items themed around Halloween but which can be worn at any time of year.
There are also four new community-made maps, called Gorge, Hellstone, Moonshine and Sinshine, each of which has a spooky horror vibe. Rounding off the Halloween selection are new taunts, including "The Broomstick," which is a flying broomstick and which is described thus: "Go riding with your best friends Robby-Bob and Herman, or enjoy a rousing game of Bibwich and snatch the catch or avoid the noid or whatever nonsense is in the stupid books that inspired these awesome taunts."
Lastly, the Mannpower Mode is now out of beta. It's not Halloween themed, but it's got grappling hooks and powerups, including a new one that allows you to give your enemies the plague.
I have taken part in a number of previous Team Fortress 2 Halloween events, have duplicates of a great many items, but can never bring myself to sell any of my hard-gotten gains. Not only because they'd sell for pennies, but because it's just about the only game I've bothered to collect this kind of thing in. I'll never let them go.