I'd stop by Les Etoffes if you're closed by as well. I love their clothes selection which is composed of great basics. In men's, I remember they hold Unis and Christophe Lemaire (of Hermès).
Not knowing what are your center of interests, it's kind of hard to propose you anything. food-wise, the most talked about restaurant right now is probably still the Kazu, I believe, which serves cheap-but-good-not-worthing-the-hour-long-wait-in-the-queue japanese food. If you like ice cream you can stop by to Le Bilbocquet on Bernard. Try bagels on Saint-Viateur which are arguably the best ones in North America
. Since you're from the US, I'd highly recommend to eat a poutine, Quebec's flagship dish, an awful mix of cheese, french fries and sauce: la banquise is probably the place to go. Schwart'z is an institution and serves smoked meat, but I personally prefer Lester's (which is on Bernard not far from Le Bilbocquet). Adresses on my to-try list includes the Lawrence, Le Filet (which is owned by le Club Chasse et Peche owners) and le Van Horne Restaurant.