Nugg2396 said:
what's the best flashcard after Acekard and M3?
Depends on your needs. Need real-time save, in-game guides, do you got a DSi, want GBA expansion capability, etc?
Acekard2i and M3iZero are the most popular because they are fairly new and support the DSi. Acekard2i gets mentioned a lot because of AKAIO, it's frequent updates of loaders (to play newer games) and the fact that the AKAIO developers are on GBAtemp. M3iZero gets a lot of mentioned because of it's bevy of features (RTS, RTG, etc) and the fact that the M3 brand is a popular brand that's been while for awhile, and gets decent updates.
EZ Flash Vi and Supercard DSONEi aren't as well known but by no means are lesser cards. Both cards rival the M3iZero in features, and have gotten really nice feedback here. So I'd check out those two cards as well. They both have unique features that are particular to that card, or do things in a unique way (perhaps better, depending on your tastes).
If you've got a DS Phat, the CycloDS still gets mentioned a lot here.
Cards that don't get too much mention anymore are the R4, which is a great card and I still use it with YSMenu, and I think homebrew support is/was good since it was "THE" card to get for awhile. The original just doesn't have MicroSDHC support (the clone R4 cards do though) and it doesn't support the DSi.
The DSTT is still a very popular card, but like the R4, a lot of fakes are out there, and newer cards do a lot more than the DSTT now.
The original EDGE card was well-received and popular (a lot of my friends have them), but it's no longer available, and is to be replaced by the just-announced iEDGE. It's not out yet, so the jury is out on whether this well be a good card the card faces stiff competition out now since there are so many good flashcards out now.