I grew up in Montreal and in fact, I was there again this past weekend for a concert (Matt Good at the Metropolis

), so I'll toss in my two cents.
Not speaking french isn't a big deal, you still shouldn't have any big trouble dealing with people and getting around. This isn't Quebec City, after all.
For food, I recommend checking out La Fleurs and/or La Belle Province. Particularly the first if it's a hot sweltering day, then sit on the terrace and enjoy watching the world passing you by. Oh, and one of those street-side pizza places downtown are hard to beat too (I call them street pizza). Also, be sure to order a poutine at least once. Nothing beats a good poutine, but they're hard to come by. If you happen out to the West Island, drop by Expo in Pincourt (where I grew up; it's on the same little island as Ile Perrot, sandwiched between Ste Anne De Bellevue and Dorion), they have killer poutine.
Wander around the old port on a sunny day, not much tops that.
Visit Mont Royale, at least once.
And be sure to take in the nightlife, it's hard to beat.
Being that you're an RPGer, then check out Le Valet D'Coeur, as another poster mentioned. It's my favorite RPG store. They also have anime, conventional board games, models, and such. Very cool place.