I listen to Rinse.fm (http://rinse.fm) incessantly for 8+ hours a day, it's got some of the best DJs in London for dubstep, house, grime, reggae, and everything in between. Always a solid listen.

Otherwise, usually anything instrumental. B.Lewis, Apollo Brown, and Pretty Lights have some great instrumental albums out now which cast a positive and productive vibe on my hack sessions.

Oh, and people apparently enjoy coding to my instrumental album! :) http://djmarmalade.com (free download, shameless plug).