Nokian's seem to do well in winter tests, not surprising really, though they don't show up in this list much:
http://www.tyrereviews.co.uk/Tyre-Tests/#winter
which is like a "best of" tests over a number of years, and seems to have only four makes/variants: Nokian, Conti WinterContact, Dunlop and Michelin Alpins.
I'm sticking with Alpin 3s/4s for this winter, partly because I don't want to change from Michelins, but I have asked the guys at DM Tyres if they're getting any Dunlops or Conti Winters. Either of these with 6/7mm tread are worth £40 a pop part-worn, IMHO...