There are many many beautiful cities in Canada.
You just need to have a close look at the economy, cost of living, and cultural entertainment of each to determine what would be most suitable for you
My personal opinion on the cities you mentioned:
Toronto - very busy city entertainment and culture-wise, weather is unpredictable, crime is an issue, cost of living is very high. Plenty of
Calgary - growth rate is off the charts which brings many problems, a lack of rent control there means your landlord can up your rent as much as they
want and as often as they want, very high cost of living, weather can range from mild to extreme. The only good thing about Calgary is the fact that
it's next door to Banff National Park. Not much for fishing.
Vancouver - gorgeous city surrounded by beautiful ocean and mountains, cost of living is extremely high, crime rate is high due to many
homeless/vagrants travelling there to live on the streets because of the nice weather. Plenty of fishing.
Regina - small city, not much by way of entertainment, cost of living is quite reasonable, crime rate is high due to the surrounding poverty, not very
clean, weather is extreme ranging from hot dry summers to arctic freezing winters. Not much for fishing in the immediate area but plenty of fishing
farther north of the city.
To be honest, when it comes to cost of living (particularly if you plan on being a renter), you're much better off living just outside of any city in
the nearby surrounding towns. Keep in mind that Canadian cities are no where near as large as US cities so travel from a surrounding suburban town to
downtown city life would only be a 15-30 minute drive at most.
Hope that info helps... good luck in your search !