First lesson of shopping in Toronto is to AVOIDE the Eaton Centre AT ALL COSTS! There is not one unique store in the awful place. The reality is, that the Eaton centre sucks your soul! There are other malls in TO is that is wha tyou are looking for, I really like Yorkdale Mall, it is one level but very large and with basically all the same shops as the Eaton Center but without the crowds and the soul sucking.
I also really like to shop on Queen St W. This area is perfect for those who really love to shop but hate malls. There are lots to look at and great deals.
Bloor street/Yorkville is of course la creme de la creme of shopping in Toronto. That is where Holt Renfrew, Chanel, Hermes and Tiffany's are located. The staff of these stores are not to snotty and don't mind people window shopping which I am happy about!
Toronto has great shopping with lots of unique places to visit, but more often then not people go to the Eaton Centre and then they hate Toronto!