As for the best card, it's debatable. The DSTwo in terms of features is the best, as it has a CPU in the card that lets it run GBA emulators and SNES emulators at (mostly) full speeds. It's the more expensive of the DS Flashcards. Then there's the choice between the Acekard 2i and one of the many R4i clones. I personally would choose the AK2i, seeing as I've had one since launch and it has yet to fail me.