Sam James Coffee Bar has great coffee. Honestly, if you're downtown skip Starbucks (they don't know how to make a good cup of coffee). It can be a bit tricky to find. Go to the Sunlife building, head downstairs and follow the path. You'll see it on your right hand side. The coffee doesn't come in silly american sizes - just normal coffee sizes. Be warned though: it is cash only!
Enjoy :)