Some people say brand doesn't matter...I personally disagree with that theory. I use SanDisk memory cards exclusively. This will probably end up under the heading of famous last words, but while people around me were using brand x cards and experiencing failures and data corruption....I never had an issue...and even when I thought I did have an issue...it turned out to be a problem within Vista and not a card problem. Prices for memory cards are all over the map....the only recommendation I will make is that you buy from a known reputable dealer. Half the crap found on ebay is fake and doesn't live up to expectations, if it even works at all.