Please post more than one letter posts, please. PLEASE.
And obviously the answer is, "whichever one can sell you a real one cheapest." They're all legit sites.
If you're just trying to get us to do the research for you that's just lazy. >_>
EDIT: you fixed it. thank you lol.
EDIT: DO NOT use adapters. those damned things fuck up and are unreliable, since they don't have proper MagicGate support (needed, all fake memory cards lack this coding and it leads to data corruption and errors constantly).
Get a LEGIT memory stick. Make sure it is REAL. Otherwise you'll have the same issue.
Try Micro Center. they offer the BEST prices the last time I checked, you can order form their website. Although I believe the walk in price is cheaper... look for the Lexar 8 GB. It's the cheapest.
Also, make sure they are fast reading sticks (MARK 2 or higher) otherwise load times will be ATROCIOUS, being such a high capacity card. I got an 8 GB memory stick without MARK 2 and it took THREE TIMES AS LONGER than a MARK 2.