Three very popular (and best bang for the buck) winter tires among several GTA tire dealers include:
Hankook I*Pike W409
Gislaved NordFrost 5
General Altimax Arctic
I am sure any of the three would work fine for GTA roads....W409 are probably best of the three for handling (see Nov 2009 Consumer Report)....T-rated so the ride won't be as squishy (I do find my Generals to be a bit squishy...one of the few cons on these tires IMO). Get some prices from Simply Tires, GoforTires, Tires23, Joy City Tires, etc.
If icy roads are your biggest concern, get the Blizzak WS70 or Michelin XIce Xi2. Not sure on how long the WS70 will last from treadwear standpoint. On older Blizzaks, one common complaint was that the tread didn't last long. FWIW, it has been reported that the rubber compound on the WS70 is noticeably softer than other winter tires like the General Altimax Arctics.
Dave