I enjoy mixes from British DJ Jaguar Skills. He applies a 70's retro-ninja style to old-skool and modern hip hop. His mixes help keep me amped and motivated. I have 1.3 days worth of his mixes on my ipod and I just shuffle through that. Just youtube him or check out the mixes he posts on soundcloud; most of them can be found there and are free
http://soundcloud.com/djjaguarskills
http://soundcloud.com/djjaguarskills