nds-card.com
They are gbatemp's official sponsor, meaning buying from them helps support the Temp!
I have heard a LOT of reports as of late however that NDS-Card has been having a lot of issues in the customer service department. Some users have reported that their shipments have been mishandled (cheaper shipping used despite paying DHL, orders not shipping out for like 20 days, items being stuck in Hong Kong indefinitely). I'm not saying that they are bad and that they should be completely avoided, but personally, I would like to see how this situation plays out, because I do recall that NDS-card was a stellar site, up until the Gateway 3DS got stock. Personally, I'm thinking it was more akin to user impatience, but hey.