Try ATI TV-Wonder, i'm using it right now, it has video-in, s-video in, audio-out, and digital VCR function, it also has channel&program lock and TV-Background display too. it's just cool, and the picture quality is amazing
my moniter res is 1280*1024 and i can put it in full screen mode with sharp TV-quality
picture. in deed, it doesn't use any cpu power too.
or try Zoltrix Tv-Turner, it has dual tvcable input( one for cable and one for fm-radio), video in adn s-video plus "Remote control".