Cafe Rico on Rachel has delicious coffee roasted daily, great prices. I like their Gato Negro blend (Wed and Sat), but they're all pretty tasty. I agree with the Cafe Union nod, too, but Cafe Rico, for my home machine, is the best--always produces a thick dark crema
It took me months after purchasing my Saeco fully automatic espresso machine to find a bean I really loved, and that's consistent from batch to batch.
It's "Just Us! Coffee Roasters Co-Op" (Italian Roast). The package claims that this is Canada's first Fair Trade coffee roaster.
I buy mine at a natural foods store in Toronto (a 5-lb bag for $59; smaller bags are available). Get in touch with the company for availability in Montreal (they also sell direct, online). For some reason, they don't include the 5-pound bag in their product line-up.