NDS flashcarts work pretty well, TWilight Menu++ works too, (only if your 3ds is hacked btw) NDS Forwarder (you also need a hacked 3ds like everyone else says) works pretty well too if you aren't trying to forward a Pokemon game like Pokemon SoulSilver. ..it freezes like crazy and makes you want...
btw i feel this a good time to remind you guys that sea of thieves was made by rare, who also made DKC1-3 and DK64, alongside banjo kazooie and conker's bad fur day