Unfortunately baseball is done for the year, and basketball locked out. Maple Leafs would be pricey. As Hammie says above CN tower etc is good. If you like wine, Niagara region is amazing and there are ice wines etc. that might be new to you.
Have a great time.
Just an FYI though, Toronto isn't a city that is representative of Canada as a whole, were a lot more laid back and friendly than you'll find in hogtown...