no$gba
No$GBA is a closed source GBA Emulator and Nintendo DS emulator. While the emulator originally started off as a Game Boy Advance emulator. It has now branched out to also offer emulation for the Nintendo DS.
No$GBA was the first Game Boy Advance emulator to successfully support the ability to play multiplayer games on the same PC. No$GBA was also the first emulator to successfully emulate commercial Nintendo DS roms.
No$GBA has successfully managed to provide highly compatible emulation for the Nintendo DS. Making it one of the best Nintendo DS emulators about as it also manages to emulate the Nintendo DS without sacrificing performance. Recent versions of No$GBA have gone as far to also offer emulation of the Nintendo DSi.
Despite a somewhat on and off development, No$GBA is still one of, if not the best Nintendo DS Emulator. It offers a high amount of capability, good performance while also being able to emulate the GBA successfully.