dunlop graspecs are your friend! - they grip like mad on snow and ice, I have tried to ebrake my car around a turn at like 15mph and the damn things just wont let go!
Now- the drawbacks - it feels like driving on marsmellows on dry ground and they dont grip much on dry. They feel downright dangerous when braking hard on dry ground as they squirm a TON. - but if you got snow and ice - get them now! Cheap and perfect - oh and they wear kinda fast on dry ground.