You'll get as many answers as there are people here! Maybe even more. It depends a lot on your priorities and your driving style.
One common suggestion is to check out the ratings and the comments at
www.tirerack.com . Start with the ratings, and then search through the comments to find those that might come from people who drive Subies or share your style of driving.
I'll start it out by saying that I've been happy with my Continental Conti Premier Contacts. I chose them largely due to high rating for snow and treadwear. I must note, however, that the more exotic a tire you buy the less the chance that you'll find a replacement readily available when you suffer an unrepairable blowout while coming down into the Hudson River valley at Newburgh, NY on a cold and windy day in February--just to cite a hypothetical example.