A few recommendations.
There is a trouffle chocolate in Costco through Christmas season, warmly received by relatives in China during our last visit. It's huge, two packs per package, around 1kg, $12 around. That will put smiles on your uncles and aunts.
Lego/Bionicles toys for boys aged 4 to 12. Cheaper to buy here.
Really good handcreams from Crabtree & Evelyn, in majoy malls including Rideau and Bayshore,something exotic for protecting your moms from the winter coldness.
http://store.crabtree-evelyn.com/hands-and-feet-treatments.html
Stainless steel cooking utensils, has to be top quality 18/10 steel, Lacostina, Hankels, etc. It's the big fashion in big cities right now, cooking quick and healthy meals. You can get 6-7 pieces pots ranging from $150-300 from various stores including Costco,Sears,the Bay, Linen Chest, etc. If you just want to pick up one or two pieces, try HomeSense or Winners.
Just my two cents. Have a wonderful trip.