Montreal is nice. Best to have your hotel in (or walkable to) the old quarter, though they more pricey. Bagels are amazing, and they have their own amazing pastrami ("smoked meat"). Walk up Mount Royal; it's a lovely park. I really love Quebec City, too, if you can swing part of your trip up there. I had a breakfast I will never forget in Quebec City, but would have to look up the name of the place.
I've been to Toronto a few times and do like the city -- it reminds me of a smaller NYC. But there wasn't a single meal I ate there that was memorable.