composite < svideo < component < antennae up your ass..
yeah the last thing is a joke ;-)
here is a breakdown:
composite = 1 wire for the video signal (everything is squished together)
svideo = 2 wires for video signal (more separation of colors)
component = 3 wires, one for each rgb
(if you want to consider the shielding as a wire, add it, but the shielding is not carrying a signal unless something is very wrong)
each of these uses shielded cabling coaxial pretty much... svideo uses a minidin which looks like (but is NOT) a ps2 plug\jack on your mouse or keyboard. composite and component both use RCA jacks.
You can make your own cabling, svideo is the hardest to make, i hate working with minidins.
i would say if you use medium grade cabling, component still beats out svideo due to the separation of signals.
You can make your own component video cables the same way you can make your own composite videos, use shielded coax (rg59\6 with rca ends).