I use a Scart switchbox for my VCR, Dreamcast & GameCube. It also has audio/video out via phono/s-video connectors. You switch input using puchbuttons, rather than auto-switching.
I find it very good quality, I don't notice any loss when playing games etc. I did try the s-video out once and it was terrible quality, but who cares when you've got RGB via Scart

I'm not sure what it's called but if you like I can find out when I'm at home...