A Sword - We got a bunch of them lying around the house.
The Shelf - Heavy but if you are on higher ground it is an instant K.O.
Steel Chair - Made out of STEEL.
Brass knuckles - People are forgetting how effective this is, and it makes a nice pendant.
Fire Crackers - Throw a bunch of them into a steel barrel at a public mall, then behold the chaotic stampede.
The Door - Ram it into their face fast enough or use it to jam their arm. If it is a sliding door made out of glass, you've won.
Chandelier - If you manage to grab a hold of one thats a lot of ammo.
Glass Cup - Bonus points if it's a heavy beer cup.
Water Gun - Go to your science class and fill it up with Liquid Nitrogen.
Snacks - After you've finished eating some snacks, there are a "Do Not Eat" packets inside, take them and mix into a Water Gun or Water Balloon.