I really find the canadian cities I visited very under-rated by Americans. Canada definitely does a better job with cities. Im a city guy and love mass transit, love cycling - I commute year round on my bicycle from the BX to UES in NYC
I found Montreal an amazing, enjoyable, clean and complete city. Midnight bicycle riding across the entire island and up to Mount Royal is probanly one of my most memorable city experiences. In addition to the fresh food markets, bars, ethnic enclaves, the F1 race track, olympic heritage, etc
I got engaged in Ottawa during its winterfest festival ice skating down the canal and the city was a lot of fun despite the brutal cold conditions.
Quebec City felt like movie studio - too clean, too perfect but the falls nearby and the overall natural landscapes, river, etc sorrounding the city makes it a worthwhile visit
Halifax, NS was a nice small city too