I have to concur with Jessie in regards to reliability of certain brand cards.
It's surprising really to see such a positive response to Sandisk where I, and many others that I know have had mixed results with Sandisk SD cards. I've had some reliable ones, but so many have also failed, become corrupted and unusable/unreadable as well. Sandisks also have a tendency to be a lot slower than their rated speeds compared to other brands.
On the other hand I've had great luck with Kingston, and they've always been faster and more reliable for me than Sandisk. As Jessie mentioned, a lot of the memory/SD cards are spat out generically from a generic location and then stamped with branding. If I personally have a tip, then the key differentiator in reliability is location, and knowing the country and/or plant your memory came out of.
I know companies like Kingston produce SD cards from locations in quite a few countries. I make sure I get my SD cards from a reputable seller, and that it is made in Japan. I hear Taiwanese produced cards can be problematic.
Just my 2 pence...