Canada is the second largest nation in the world so study up on what you wish to see.
You can see Ottawa in 2-4 days, and thats if you want to see everything. If you just want to see the god stuff, a day will do fine. Toronto however has everything and you can't see everything and there are so many things people forget to put out to the puplic to see. In my own backyawrd there is the Gibson house pretty much and few people who live around me know about or have seen it. So I'd say even if you stayed here for a year you'd not see everything in Toronto.
BUT.... You are from New York, Toronto is known as the Green New York, as we have trees everywhere even in the city. So well maybe Toronto isn't different enough for you. I've been to Vancover and it's pretty nice over there. I'm guessing even though Vancover is a lot more further to go to the ticket most likely isn't that much more to buy for you. I'd go there before Toronto since you are from New York. The only problem with going to Vancover is you can't see Ottawa. See if you go to Toronto you could always catch a regional flight to Ottawa for a day or two and I think they are pretty cheap still. So you should either do Toronto/Ottawa or Vancover. However there is not as much to see in Vancover as in Toronto so you might get board there if you go for any long lenth of time.