1) Waterloo, which everyone sees as a ticking time-bomb because of Rim.
and
2) Mississauga, which is Toronto's sprawl and is where all our soulless corporate code is written.
Fortunately, I work for a hospital.
Don't get me wrong, there is a lot of great stuff going on in Waterloo and I love living here, but Toronto is so much bigger and has so many more opportunities its not funny.
Waterloo has a population of 100K people. If you include Kitchener and Cambridge then you're up to 400K.
Toronto on the other hand is the 10th largest city in the Americas[1]. To put that into perspective for Americans, that means that if you live in a city in the states that isn't NYC or LA, then Toronto is bigger.
1. http://en.wikipedia.org/wiki/Largest_cities_in_the_Americas