Kind of late to this too...not sure what your budget is but what about a Toronto City Pass...
It's a great way to see some classic Toronto attractions that tourists and Torontonians usually like (or should at least see once):

Royal Ontario Museum
Ontario Science Centre
Toronto Zoo
CN Tower
Casa Loma

We go to the ROM, Zoo and Science Centre every year. The Art Gallery of Ontario is great too (we have a membership so go more often). Or maybe just a gift card to one place that they haven't seen (I'd skip Casa Loma's not that exciting IMO)

And you can't forget ketchup chips! when my friend moved to Florida she really missed them because she said that they don't have them in the U.S (but that was probably 10 years ago...they may be available down there now?)