There are too many people nominating games that aren't bad, Come On Donkey Kong Country? Battletoads? and many others especially SOM and SMK, if you don't like them personally don't say they are the worst on the system. I'm guessing that people who nominated those games haven't played too much of the SNES library before if that's all you can come up with. IMO the only people who should voice their opinion are ones that've played many games maybe hundreds for the console and get a good idea of the good and bad.

That said, I actually have two more games that surprisingly haven't been mentioned at all yet.

Musya - I picked this up from a video rental boxed and all hearing that it was supposed to be a great and scary game and a top game in Japan. When I played it, I was treated to an aweful Castlevania clone with horrendous sound and the most boring game play I've ever seen on the SNES.

Super 3D Noah's Ark - Ripped from the Wolfenstein engine, Wisdom Tree gave us one of the most cheesy and bad/grainy/pixelly looking FPS's ever to grace a console. Every level looked the same, the framerate was about the lowest I've seen on the console and your weapons were slingshots that were upgradable. As bad as the game is though, its still great to play just to laugh at.