I agree with Bryan on some things. What exactly are you looking for? Vancouver is better for visiting than it is for living; cost of living is really high, and while there are lots of fun neighbourhoods and punk rock goings on, it's not the best city for Fun Things To Do. The weather there is weird--not a lot of snow, but the winters are long and dark and cool but not cold, and the summers are short and bright and warm but not hot. There's also lots of drugs.
Toronto pretty big, which gives it an advantage in a lot of ways--there's a pretty great arts scene here if that's what you're into, lots of theatre and galleries and whatnot. Lotsa music, too, whatever you're into; we've got big little scenes (indie "rock", ska, punk, etc.) as well as numerous giant arenas. I don't know what line of work you're in but it's usually pretty easy to get a part-time job close to home (unless you live in, like, missasauga or something). Not the cheapest place to live, but not as expensive as Vancouver. Bryan is right, though; it is probably one of the ugliest cities ever. Winter is depressingly long, but not too cold.
Montreal is fantastic if you can handle the absolutely freezing winters. Rent is super cheap and most laws favour tenants, so you're pretty much covered, housing-wise. It's lovely and artsy and there's basically nothing bad I can say about it. It can seem intimidating if you don't know French, but I disagree a little with what Bryan said--I've always found that there's a pretty big anglo community, and it's not so hard to get a job if you look in English-speaking neighbourhoods. It does help if you at least make an effort to learn some French, though. People appreciate it and will treat you a lot nicer.
Halifax is really lovely and actually has a great music scene (plus there's more art than you would think; NSCAD turns out a whole lot of talent), but yeah, the university students on near-constant drinking binges can start to grate on your nerves after a while. Also, it's super expensive to get to or from, even by train. Also: horribly cold in the wintertime.
Ignore Julie (sorry Julie!). Please don't move to Saskatoon.
