Biggar Saskatchewan's motto is the best
A lot of cities tend to either promote their industry like Calgary's "Be A Part of the Energy"
Some like Saskatoon's promote their climate like Med Hat's "Sunshine State of Mind"
Some like Regina promote both their commerce and geography "Infinite Horizons"
Some hit the mark off a bit, Moncton's I believe at one time was "Our Tide is Rising" which just seems a little ominous... especially if it's Red tide.
Other's like Mississauga's uses a little bit of humour "I'm With Stupid
→" kind of like how Vaughan uses it's proximity being "Above" Toronto.
But could be worse, Toronto's "Hog Town" because of the people there or "The Big Smoke" because of it's heavy smog, even back in the days when people smoked more are even more demeaning.