The perfect Winter tyre does not exist, I live in the Yorkshire Dales, lots of rain crud and ice and I ride all winter.
I find that slick tyres are just as good as anything else on slippy roads, tyres with treads are okay for deep mud and off road riding but are no better than slicks on plippy roads and also they have a much poorer rolling resistance.
Go for Hutchinsons Kevlar they are cheap and last ages, I use them all winter and buy them from Ribble Cycles, they are the cheapest that I have found and you get free innertubes.
Barrie Cartledge