Christian hip hop duo Social Club has their whole Mifits album for free on Noisetrade! You can get it here.
Jon Foreman, lead singer of Switchfoot has a free sampler called Old Seasons, New Day that reflect the different seasons we go through as Christians. You can get that free here.
Winter Jam has released a sampler of 5 songs from Tenth Avenue North, Plumb, Thousand Foot Krutch, Derek Minor and Newsong, to help promote their Overflow Devo. You can get the free music sampler here.