I run Panaracer Urban Max 32c tires on my commuter. Not the liveliest riding tires available, but they provide good protection from road hazards, and enough traction for mild off-road riding. It's no fun trying to fix a puncture on the side of the road when it's dark and below freezing, so I'm willing to sacrifice ride quality for peace of mind. Last night's ride home included ~3 miles of dirt, about half of which was covered in light snow. The aforementioned Panaracer's made it seem almost easy.