I seriously wouldn't recommend memorex DVDs. Their CD range was pretty good, but the DVDs seem to be faily substandard by way of the acrylic used and the writable surface. I've no idea what brands are available in Canada, but here in the UK the Datawrite range seems to be the one to go for.. and also Ritek dye disks if you can find them.
Verbatim and TDK still get a good name, but if you grudge paying DOUBLE the price for those (as I do!!) then I'd steer clear.