There doesn't seem to be a poll option, so lets just post our opinions. Only answer if you have played both.
I have to go with the Genesis. I have played both many a-time and I can't seem to convince myself that the SNES was better. Sonic II, Street Fighter, NBA Live, it just doesn't get any better. Super Mario World was cool, but it got very frustrating and had no replay value.
What do you think?