I am not the biggest fan of shopping malls, but I have been to Eaton Centre several times and always had a pleasant experience, also found what I was looking for.
It is difficult to find things though, the mall is HUGE!! But still a good choice if you have time and are prepared to go through hundreds of shops, booths and what not.
Also it is nicely decorated on Christmas, worth the visit if you do not mind walking through crowds of people.