Around Montreal, you can have the best coffee, IMHO, at Java U. Also, independent coffee shops, especially Italians, serve good coffee too. As a caffeine-addict, I don' t care as much as it contains caffeine, no I' m just kidding.
Personally, I absolutely love Starbucks coffee. However, I'll admit that it's extremely expensive. A lot of people I know swear by Caribou Coffee, but I'm not much of a fan. The Wild Bean Cafe at bp is pretty good, though.