Lots of bigger chains in our neck of the woods. Kal Tire, Fountain Tire, Integra Tire (formerly Tirecraft) come to mind. I've used the latter for quite a few years and have been pretty happy.
Too bad we don't have a Tire Rack type operation (like they do in the US) here in Western Canada. I seem to recall there is a place in Vancouver that has a similar business model, but for the life of me, I can't remember their name.
Any time I'm looking for info on local type automotive businesses, I scour the archives over on
beyond.ca. OK, they tend to be more of a ricer focused website, but you can find good info on places to go to and places to avoid. It's a Calgary hosted site, but lots of people from all over Calgary, Edmonton and the rest of Canada on the site.
A word of warning about Beyond. It's one of the most unmoderated sites I've ever been on. It can get a little crazy there now and again. Plenty of trolls.