Just came back from a 3 day stay in Montreal...

I'm not sure how the city pass works. But I can't think of that many worthy sightseeing spots that have admission charges. The city itself is the attraction: the streets, the architecture, and the festival ambiance under the nice summer sky. You can enjoy the city by simply wondering around, and joining the locals in open markets and the numerous outdoor cafes. And as the previous commenter said, the food there is just incredible, and cheap especially with the low exchange rate between CDN and USD ;) If you're into nice food, you should definitely check out Joe Beef and Au Pied de Cochon, two of the restaurants profiled in Anthony Bourdain's "Parts Unknown" (Season 2013, I believe). Make reservation early (meangin weeks in advance) as they get booked quickly.