Well I live in downtown Ottawa, which means:
I'm within a ten minute walk of two different grocery stores, a major mall, my work, and rapid transit, the main library, theatres, museums, and several community centres and parks; there are bars, restaurants and coffee shops almost literally right outside my front door; and there are always interesting events and festivals going on nearby.
So yeah, downtown Ottawa is pretty great.
I live in what one might call midtown Toronto, but it's basically like a downtown - I have a 24-hour supermarket, a shopping mall, two movie theatres (there was a third, but it was turned into an "event theatre" a few years ago, and is now rented out for things like weddings), and more bars, restaurants and coffee shops than one can shake a stick at within a five-to-ten minute walk. The mall is a little on the small side, but it's got a liquor store, a record store, and a major bookstore, which is all I really need from it (well, besides the supermarket - I need that too).
I was in Montreal this weekend (actually, I'm posting this while sitting on a VIA train, just west of Belleville) and there's one mall on Ste-Catherine that has always struck me as being nearly a complete waste of space. It's called the Faubourg, and whenever I've gone in there, it's seemed empty. (The bare concrete floors aren't very inviting, either - it makes the place seem even more abandoned.) There's a food court on the second floor, which is really the only reason I ever visit it, but I don't think I've ever seen more than three or four of the counters open. I'm told it's busier during the week, but since I'm only in Montreal for one weekend every year, I never see that. (Okay, last year I think I spent three or four weekends in Montreal, but I was working on the Worldcon, so that doesn't count - and besides, the meetings I was attending were further east, and I never got over toward Rue Guy, which is where this weekend's convention was.)
Yeah, Downtown Ottawa is pretty neat. I'm partial to the Market area.
I used to live in the Market, but it tends to be really touristy and overpriced. I live off Elgin Street now, and much prefer this area.
I lived for four months - during my May-August 1989 work term - on York Street. I want to say that I lived at 525 York Street, but Mapquest says there's no such address. It was something like that, anyway. All I really remember is that it was just east of the section of the street that's closed to vehicular traffic, where all the bars are. Let's just say that it was an interesting experience, living there. I think I spent a little more money that term than I should have, because the bars were just a little too close.
One of the hardest things is figuring out what to do with your Friday night, there are too many options 
