I tried a load of em yesterday from the Weirdo hack where all the pipes and monsters are now very poor pictures of male genitals to the Mario Smokes a Doobie hack.
There is a Pimp hack, a Black Mario hack, and the only one that was amusing in any way was the Double Dragon Mario hack where the lead character had Mario's head on his body.
Play em for a 10 second laugh if ya like but they arnt anything special.
NES games by the way, and a few for the SNES too but edgeemu has most of em.