Garage sales and charity are two great options. People are always looking for a bargain and there is a whole philosophy surrounding garage sale etiquette. It's a great way to make a few extra bucks and your unwanted stuff will go to people who will appreciate it.
Another great option is giving the stuff to a charity, so that it goes to helping a charitable business who will resell your donated goods. These goods area also usually sold at a vastly discounted rate which is great for bargain hunters!