Kitchener: Not much in the way of beer being made here.
Guelph: Wellington Brewery, F&M, Woolwich Arms Pub (for cask ale)
Toronto: Lots and lots of places! Bar Volo, C'est What, Mill Street... There are too many for me to list and I'll leave that to somebody else. I'm in Cambridge so more familiar with the Guelph, KW area.
If you do decide to come further south to Cambridge there is Grand River Brewing (where I brew a couple of days a week) and my place! Let me know and I'll work a brew day around you.