I was able to find some more info last night at tomshardware.com. The article was written in dec of 2001, but it had a table of which geforce cards had full-screen tv-out ability.
It boiled down to the fact that only the cards with VI/VO (they use a combo Philips chip) did s-vid out like the ATI's do. All the others (VO only, like Chrontel, Conexant) had borders and/or uncentered images.
The only cards I have found so far that have VIVO are an ASUS, an MSI, and a Gainward.
As far as daphne goes, I compile the latest daphne source every so often. But, the dvd2daph utility should work to convert the vobs for you. The only issue is that if you have an ATI card, they don't like non-standard resolutions. So, in that case, you should use dvd2avi and tmpgenc to re-encode each .vob to an .m2v and .ogg (like dvd2daph does), but change the resolution to 640x480. There are only about 100 files to re-encode.
Now you know why I want a Geforce!
Dvd2daph created the .m2v and .ogg files just fine from my dvd-rom. Make sure you have the DVD-ROM, and not just the plain DVD.
I hear the MACH3 is being worked on, but isn't done yet. Check your private messages...