as asked, where are you staying? in the city or suburbs? will you have a car?
catch a Blue Jays game, CN Tower, Hockey Hall of Fame, check out the Distillery District, Royal Ontario Museum (ROM), Art Gallery of Ontario, Eaton Centre (huge downtown mall), St Lawrence Market, Canada's Wonderland (amusement park with a solid selection of coasters), make a trip out to Niagara Falls if you've never seen it
good streets to wander, Queen St. West, King St. West, The Danforth (Greektown - Bloor St East), Bloor between Yonge and Spadina (Yorkville, kind of like Toronto's 5th Avenue), Yonge & Dundas Square (our version of Times Square), Spadina (china town), Kensington Market
food-wise, depends on where you're staying and how far you're willing to roam the city....good food all over the place...
couple places i love that are cheaper/casual:
http://su****oronto.ca/2009/03/aji-sai/ - should read "sushi toronto.ca" without the space
In a closed society where everybody's guilty, the only crime is getting caught.
In a world of thieves, the only final sin is stupidity. - Hunter S Thompson