When I can, then 6music on a radio, occasionally on my phone*. Mostly I have to listen to whatever someone else puts on the radio in the room I usually work in, which is mostly one flavour of Absolute or other, which is tolerable.
When it’s Radio 1 then I can rapidly turn homicidal.
If not the radio, then my phone or one or another iPods, either through ‘phones, or through the car radio head-unit.
At home, mostly CD or iTunes streamed through my amp from my Mac Mini.
*Strict security means most of the time my phone has to be in a locker, but there are occasions, like at the moment I’m working in a low security area so I can listen to 6Music for a whole working day!