I recently got an S-video cable for my PAL N64 from consolegoods.co.uk. It looks great on my CRT; much better than composite and way ahead of RF. The trouble is that on every HDTV I've tested it with, I get a weird rainbow effect with the colours.
The video shows what I mean:
Any suggestions? With both the CRT and the HDTV I'm using an S-Video/composite to SCART adapter.