I myself was looking for an S-video cable for connecting my SNES just last week.

I've heard that a lot of the 'no name' generic brand ones are garbage, so I wanted to try finding a nintendo brand (1st party) one. I found out after searching, it's no easy feat!

I saw on eBay (link here) , that there was a japanese seller selling Super Famicon ones (1st party), and am told they work with the North American consoles.

Figured I'd share.