I'll second the Nokians. I had them on a MTB 29er commuter and they are just too slow for that application and they do not dig in enough on singletrack. I much prefer the Ice Spike Pros for this application, although they are even wider they grip much better and I think better rubber.
On my commuter I use Marathon Winters and VanHelga's on my fatty for this time of year, although with no snow I still have on my Fat B Nimbles.