Im experimenting with different cables i can get my hands on to see which is the clearest screen that can be achieved. Sadly i don't have access to everything i wanna try but i thought i'd share my findings and wanna hear what others are doing. just to say, im not a tecky person, this is a simpleton's findings.
I have 2 HDTVs so obviously not the best choice for retro consoles, that would be CRT TVs however space tells me i already have enough big things in my house so i gotta make do.

Before today, i had been using gamecube Composite cables (red,white,yellow) for the SNES, N64 and Gamecube, however i had enough and did alittle research. I came to beleive that S-video was what i needed, however it turns out s-video gamecube cables are a bitch to find, however i did find a RGB scart for £3. The difference between a regular scart and a RGB scart is like the difference between component and composite, that said it made a HUGE difference! Gamecube looks brilliant an RGB cable! however i then tried it with the N64 and SNES which did not really work, the SNES showed the nintendo logo crisp and beautiful for a moment before fading next to black. After alittle research i found all you have to do is open up the scart plug and remove the 3 compacitors inside and solder the loose wires back in place, details here
http://www.mmmonkey.co.uk/console/nintendo/pal-snes-rgb.htm, after that, wow, stunning picture! Saddly though, the N64 still didnt work as it does not support a RGB output. Im hoping s-video will work instead though.
So my current set up to my 32 inch HDTV is:
NES - common red and yellow composite cables, looks **** aweful
SNES - Gamecube RGB scart (modded, removed compacitors), fantastic
N64 - Gamecube Composite cable, not great
Gamecube - Gamecube RGB scart, crisp and wonderful
Wii - Wii Composite cable, perfect
What i really want to know is how does RGB compare to s-video? Can anyone shed some light on that or maybe have a spare s-video gamecube cable they can send me to mess with?