s video cable

Cables equipped with RCA-type connectors can be either better or worse than S-video cables. The triple set of RCAs in a component video cable will give the best picture, if your player or receiver can use it. The single RCA connector of a composite video cable is the least expensive and the poorest performing.

From worst to best:
Composite(single yellow RCA)
S-Video
Component(red, blue and green RCA)
DVI
HDMI

S-Video Divides the Chroma and Lumance. It provides a
MUCH better picture than Composite(Yellow video cable).
However, IF recording onto a DVD recorder, use the
yellow cable into the DVD recorder. The prosessor
in the recorder will make the picture BETTER than if
you went in with S-Video.

Well, here goes! I believe S cables split the video signals into chroma and luminence signals. The result is better color rendition and clarity. Composite RCA is less desirable in that the whole video signal is lumped together. COMPONENT rca cables are a different story altogether. I assume you're refering to the yellow composite 75 ohm video cable when you speak of "rca video cables"
Sat receivers and dvd players are much harder to recomend. A lot more choices there. As far a dvd players, try the Secrets of Hometheater website

www.hometheaterhifi.com/main.html

Navigate to the bottom of the page and clik on "Benchmark" to access there dvd comparison reviews. Hope this helps.

Coax.....bad Interlaced 480I
RCA......better Interlaced 480I
S-Video..even Better Interlaced 480I
Componet Video..VERY GOOD Progressive scan 480p,720p,1080I
DVI......Excellent Progressive scan 480p,720p,1080I
HDMI.....Excellent (both audio and video from one wire)