Todd from RetroFrog has just released his fully-shielded composite video cables for the Genesis 2 and PC Engine / TurboGrafx-16. The cables are $20 each plus shipping and should be a good, reliable option over low-quality alternatives:
I think the most appealing thing about these cables is audio: While sure, you’re not going to get a massive upgrade in composite video performance, what about people who want to game on a CRT, but listen to audio through good speakers? These cables don’t add any noise to the audio and are well built with the proper cabling to ensure that there is no noise or crosstalk.
Consistency is also something to take note of – Many cheap cables can arrive with the L&R audio swapped, loose/too tight cables or worse. It’s totally up to you, but I’d personally rather pay a bit more and know I’m getting something reliable.