Murk, I love Montreal but I'll try and answer this question without mounting a defense of it!
First of all I have to say, prepare yourself for a financial shock in Vancouver (and, compared to Montreal, any large city, really - Montreal has a MUCH lower cost of living - housing, food, entertainment, almost everything) if you're thinking about it. Vancouver is beautiful (I'm a BC native) - if you like the sea/beach and outdoor activities, it's an awesome place, but cost of living is high. The vibe is also quite a bit different in Vancouver. I find Montreal to be a more relaxed, accepting city, but I'm not very granola or environmentally minded. Vancouver can be, to me, the city of the wealthy Prius drivers. Again, not necessarily a bad thing, but not my personal vibe. My overall opinion of Vancouver is positive - I'm nitpicking.
Toronto is a tiny bit of a meh for me. Expensive. There are some Ontario types here who will have more informed opinions.
Edmonton holds a small piece of my heart - unpretentious, blue-collar city with a kind of rednecky but friendly scene. Calgary, forget it unless you either have a lot of $ or you have some skillz (because they pay well, esp. in the oil patch, for specific skillz).
Can't comment on any maritime cities but my ex thought Halifax was Canada's most liveable city...
"Only an irrational dumbass, would burn Jews." - Jaguar
"please give concise answers in plain English" - request from Provoker