The brand/speed of your card will depend on your camera but in most cases it doesn't matter. As for the price, I suggest looking at a few online sites to compare the prices. Here are a few to start with:
Those are a few ideas for you, you can also check the local dealers which will vary depending on your province. In General I find that Cendirect and Tigerdirect offer better prices, but the advantage is not always so significant after transport cost are considered.