I try to listen to things primarily composed melodically and doesn't have too much emphasis on rhythm or is too chaotic. Melody is great for getting the noodle rolling, but even as someone who plays drumset, I can't get in the zone with the drummer going crazy (even if it is awesome). But I can't use headphones or have it too loud because it'll be too overpowering/uncomfortable. I prefer my rock music to have a tenor singer because it puts me in a trance. Some mellow jazz for the chillaxing effect, and pop-punk for hyping myself up with energy.
Some things I usually listen to are Circa Survive, Reign of Kindo, Tides of Man, Four Year Strong, and Emarosa (if anybody here has even heard of any of these bands =/). I don't necessarily "recommend" these bands, but they're some of my favorites. Bowie is good, The Black Keys works, Weezer in small doses...
As many people have stated, it depends on the mood.
For light-hearted drawing, actually almost anything works for me. However, I'm more particular when it comes to darker pieces. Usually dark ambient or doom metal when there's nothing moving in the drawing, and when there's a great deal of twisting and implied movement I just switch to technical death metal.
I listen to Sun Kil Moon or Soul whirling somewhere to concentrate my current drawings.
I chose a few songs I'd like to share the people's forum: Sun Kil Moon - Blue Orchids [link] Sun Kil Moon - Carry me Ohio [link] Soul whirling somewhere - Flightless [link] Soul whirling somewhere - One of these days some eyes will be opened [link]
I'm not into dubstep or techno music so much, though. Sorry.
Well, I like anything from the YouTube channel baxylz. He does all my fav soundtracks in long mixes so you don't have to switch. But let me say MrSuicideSheep's channel is the best. Progressive house/liquid dubstep/chillstep is all great.