I've had tinnitus for as long as I can remember, so "silence" for me means non-stop high pitch ringing. Thus, I use Pandora just about every hour I'm awake and around a controllable sound source.

For coding I usually pick techno, electronica, soft rock, classical, or more piano/instrumental types. It mostly depends on mood. I tend to avoid things with lyrics for coding.

More specifically, I've been addicted to Explosions in the Sky and Trifonic for months now.