SCART

Overall it's roughly equivalent to the S-Video standard US had.

SCART uses RGB as the video signal and is therefore uninterrupted from console to TV resulting in the highest quality pixel perfection you can get on a CRT SDTV.
On the other hand it has slightly lower sound quality and the impractically shaped SCART plug has an electrical charge going through when in use, and if removed/plugged in while turned on it can actually damage your equipment if you're unlucky. I have been shocked by SCART cables a couple times and wondered what the hell that sting was before I read about it.
The odd shape of the plug also makes it a pain to plug in/unplug behind your TV if you want to switch to something else, if like me have multiple systems this is not the way to go, also SDTVs as a standard come with only one RGB SCART hole on the back, the second SCART hole is for S-Video adapters and if used with an RGB SCART cable will either downgrade the RGB signal to Composite standard (with dot crawl and everything) or not work at all with a black, static or scrambled image.

S-Video on the other hand, just like composite cables, has better sound quality with the separate RCA plugs for left and right stereo, but S-Video (with it's far more practical simple designed plug) downgrades the video signal into basically two things, color and grayscale, so while the black and white grayscale signal is just as good as RGB SCART when it comes to pixel perfection the color signal compresses ALL the colors into one signal and it suffers from some color bleeding effects as a result, red color especially hence the name "color bleeding". Though it should be noted some systems have far superior S-Video coding than others it can never truly look at good as RGB does over SCART even at the best of times, but systems like Dreamcast and Xbox 360 have such excellent S-Video rendering that the color bleeding is kept virtually nonexistent, you'd have to compare side by side with virtually identical TVs to tell the difference between RGB SCART and S-Video on those two, it's that close. Regardless, S-Video is still a far superior alternative to RCA Composite or RF antenna cables.

Personally I used SCART for just about everything a few years back but has since changed to S-Video on most things, only those that are rarer to find or have unusually expensive S-Video cables still use SCART.

I remember seeing a comparison video of different video inputs for the Dreamcast and thinking SCART was by far the best. Wish there was a way to get it in the states.

Though Raven's post makes it clear that SCART has some drawbacks.

Another interesting downside with RGB SCART on Sony brand consoles in particular is that they only sync on green, so unless you have a sync on green CRT SDTV (very rare) you won't be able to watch DVDs on a PS2 or PS3, you'll just get a green screen with sound. Games still work fine though for some reason.
Also all types of SD cables (RF, Composite, S-Video and RGB SCART) when used on a PAL region PS3 automatically disables Blu-ray playback and downgrades 60Hz to 50Hz with all other options grayed out in the PS3 XMB menus. The PAL region PS3 requires Component, HDMI or other types of HD cables to use the Blu-ray player and to get 60Hz playback.

The difference is real and it's SPECTACULAR.

LOL at the Seinfeld quote.

Raven, your info is awesome. Are you some sort of A-V guy? Thanks for the info. I wish I could see the difference, but I don't know anyone who has access to SCART. I know the You Tube videos exist, but I'd rather see it in person. I have heard of Atari Jaguar people modding their systems to output through SCART, because the stuff is on the inside, but the port was never made. I wonder if actually looks better?