I use that scart to component converter that was linked a few posts up. I highly recommend it. if your console can output RGB (most of them do) you will notice a huge difference in picture quality, even over s-video. really, it's the closest you'll ever get to pure RGB on an american television.
Genesis looks amazing through it, and you don't have to fool around with an s-video mod. the only problem is the converter doesn't have audio outputs, but if you are using a model 1 genesis you can just pull the audio from your headphone jack.
You could also use something like this to get your audio
http://cgi.ebay.com/3-WAY-AUTOMATIC-SCA ... .m63.l1177
If you do get that converter keep in mind that it comes with a UK type power plug so you'll need to find one that will work in a US outlet. luckily I had an old cable modem ac adapter that worked fine.