Of all the Atwood novels, I like Cat's Eye the best, which is so rooted in Toronto as a place. Haven't read that in ages and should give it a go, though it would have to go towards the bottom of the list. I have reasonably high expectations for Oryx and Crake and its follow-up, The Year of the Flood, but haven't read them yet.
I've read Cat's Eye too, but as my only experience of Toronto was to change planes once at the airport and given my fondness for science fiction, you'll appreciate that I like the others better. O and C is really good and the other very thought-provoking in what it has to say about humanity and the ecosystem.