Nice Ottawa pics, fantastic Montreal shots!
Hey, like Oprah once said - everyone can win at the layers game! You get a layer award, you, and you too!
Montreal in terms of architecture wins this going away plus they do have some nice elevated terrain and the St. Lawrence.
Overall it's between Vancouver and Montreal with Toronto not far off. Vancouver because on a good day in a lot of locations you get views to American peaks, all the local mountains, ocean, river, layers of snow on the mountains for a chunk of the year, plus multiple skylines and varying layers of buildings and density even if that's not as impressive as older cities. As with the Montreal shots this is an aerial view, but you can much of that at ground level as well:

Skyline from Cypress Mountain by
John Grantham, on Flickr
Other Layer Winners - St. John's, with Hamilton and Quebec City as honourable mentions.