I have lived in Montreal for several years and every time I come back to the city I do not miss the chance to go to 3 Brasseurs. I prefer this location (St. Catherine/McGill College) but have been to all of them (St. Denis one, Old Port, Crescent, Laval etc). I do not think there has been a single time in the maybe 20-30 visits minimum that I was ever disappointed. No joke.
Beer is always excellent and they make their own. Any of them would do. My gf loves the beer cocktails they make she always has a few when we go. As for the food, I always love getting the Flammkueche (flatbread pizzas) which are incredible. Has other things as well, such as the chicken skewers, burgers or pork - and again never was disappointed. One thing that they could improve on is their poutine - not the top I've had in Quebec...
All in all - everytime I go to Montreal I must have some 3 Brasseurs - and everytime I leave a happy camper!