My favourite coffee downtown, and maybe even in Toronto! I've tried some of the other popular coffee shops in the financial district and on Queen West, but find myself going back to Mos Mos again and again.
I've had their regular coffee (skinny double), flat white (so smooth!), and cappuccino (my favourite) - they never fail to disappoint. The coffee/espresso is very aromatic, and the steamed milk (for no extra cost) is the perfect touch. There is quite a bit of foam even with skim milk.
The baristas are also generally very nice and service is fast. They also do cute latte art no matter what drink you order. Overall, Mos Mos to me is an unpretentious place that serves good coffee. Now if they only expanded to a location where one can sit down for a while on a chill weekend afternoon.