Chez Ennio is hands-down my favourite restaurant in Montreal. I've been there so many times over the past three years, and the whole experience is like nothing else - I don't have wonderful Italian grandparents to cook me fabulous food. Ennio gave me this card when I showed up with a party of five on a busy Thursday night, and I managed to put my foot in my mouth by trying to explain that it wasn't usually too busy during the week.
L'Enchanteur is a lovely pub and restaurant up near the Jean Talon market. I went for brunch, which was very good, and not too expensive, but also not worth the hike. They serve their water in old wine bottles, which is very rustic chic of them. It was an excellent place to chat with friends for an hour or two.
Los Tios is on Crescent street, and is notable for its teensy tiny patio, awesome lunch menu, and delicious sangria. It's perfect for soft shell tacos and sangria on a hot summer day. Even though the terrace is tiny, it doesn't get as busy as the huge patios around it so I've never had trouble getting a seat outside in a small party.
Machiavelli is very conveniently right across the street from the Charlevoix metro station and next to a SAQ. The patio is in the back and has a lovely backyard feel. The food isn't cheap, but it's not terribly expensive either, and the kitchen only runs a few specials each night so what they serve is good. There are some basic pasta and meat staples for the picky eater, too. BYO wine makes it a very affordable nice dinner out.