I'll vouch for Toronto- it's where I'm from.
I loved living there, it's a fantastic city. Very multicultural, lots of great restaurants, bars, pubs, clubs, shopping. There are so many different types of neighborhoods in and around the city. North York, Queen West, The Annex, Danforth, Little Italy, Chinatown, St. Lawrence Market, Forest Hill, Rosedale, Thornhill, Richmond Hill, Mississauga, to name a few.
The Maple Leafs, The Blue Jays, The Raptors, Toronto FC, The Argos, and now The Bills.
A very green (both ways- lots of greenery and a good recycling system) city. Some very nice parks in the city, with horseback riding, public pools, tennis courts, golf courses, etc.
Every summer, there is a festival every weekend. TIFF, Taste of the Danforth, Canada Day, Caribana, Gay Pride Parade, Taste of Little Italy, Woofstock, etc.
A one hour drive north, and you're in Barrie, and a little further and you're in Muskoka. Lakes, trees, hiking, camping, small towns. Nice hotel-resorts, bed and breakfasts, etc.
A 90 minute drive south, and you're at Niagara Falls and a little further, you're in the USA.
As I said, I loved living there. I miss it- but not this time of year. It's freezing! I moved to LA for the weather!
Hope that was helpful....