AudioJungle is part of the Envato network (as GraphicRiver) and it is a Audio/Music stock site. And every month they feature a free file to download. You just have to register, and its completely free!
This month they have a Hot and powerful breakbeat track with lots of energy for your intro / trailer or sport montage to add that special gritty vibe. So hurry and get it until the end of October.
Here is the link!