I was recently given a VCS 2600 and instantly set about building a composite video adapter, so that I don't have to put up with RF interference and fuxxy colours/bad sound.
I built the circuit in the 2600 FAQ and it worked very well -- i.e. the picture is crystal clear and the sound is perfect. The only problem is that on a TV all the colours are a shade of green, and on a computer monitor (the one I used to use for my Atari ST) the whole picture is in black and white.