I've ordered lots of stuff from the states, and the "Brokerage Fees" really hurt, that's above the GST & PST (15%) OMG.
USPS (Sometimes the Canadian Gov't let's us get away with things)
FedEx: 50% Chance the destination address gets a bill for the taxes.
Absolute Worst Carrier to ship to Canada: UPS, do not ship by UPS. Their brokerage fees are enourmous, sometimes up to 40% of the cost of the product. OMG
Good luck, hope this helps.