I vote for Regina because it is not officially or culturally bike friendly in the least. The roads are a mess, people are rude, people think you are crazy and everybody gets a car as soon as they are 16. But I absolutely loved biking in Regina and it is almost the only thing I miss about the place. The big sprawling Wascana Park and parklands have paved and unpaved bike/walk lanes that go throughout the city so I could get everywhere without being on the highway or roads very much. I also developed my own bike route system of quiet roads as opposed to busy roads where I might get run over. I could take so many different routes to the same destination. Plus Regina is small so even traversing the entire city didn't take too long.
I was there last year and even with all the fads and movement in cycling I saw very few cyclists. People were still riding ridiculous mountain bikes when Regina is PERFECT for fixies and road bikes. I didn't see one fixie.
Biking in Regina was fun and free. Vancouver has loads of infrastructure but it's stressful and sometimes there are too many bikes on the bike lane!
I would also say many rural areas in Canada are bad for cycling.