I've visited Toronto several times. A trip up in the CN tower is worth doing--I think it is, or was, the tallest structure in the world. You feel like you're in an airplane when you're up there.
If you're into shopping, head for the Eaton center. Lot's o'shops, the Bay Co. (once the Hudson Bay Company) has a nice old-fashioned multi-level store there, with cool food shopping in the basement.
There is good theatre there. I recall a half-price day of show booth across the street from some of the prime theaters. I saw "Phantom" in Pantage's theater there some years back--excellent!
They also have a fine museum there (Royal Ontario Museum?) that has some cool Egyptian artifacts, including mummies.
Toronto is a wonderful city--have a great time!
JP