the best one I have found is www.emuasylum.com its got some cool emulators and pretty much every game ever made for that console........although saying that some games they don't put up for legal reasons....however they do put lots of hacked versions of the same game up (so for super maio bros 3....you might have to get super bald bros 3 which is the same game [levels] but mario is bald.)
I can also get super mario 64 for the n64 emulator......fi you want it...........just let me know if you do HAHAHA!!!!!!!!!!!(