Now that the "Montreal summer" is officially here :-) I think it would be appropriate to compile a list of terraces, along with your preferences about them...
To start things off (in no particular order)
1. Victoria Pub. Good for drinks and concrete
2. Aszu. Small and romantic
3. Saint Elizabeth. Cheap beer, vines and university students
4. Nelligan. Expensive, with a roof top view
5. Boris. Extremely nice terrace - horrible food.
6. Bâton Rouge. Nice pit stop downtown.
7. Taverne Sur Le Square. Swank
8. Narcisse. Pretty gosh darn kick-ass