ATi TV-Wonder
I got it for $110 Canadian at a retail store
It has Coax/RCA/SVideo input
It's a standalone PCI card
it can do video captures driectly to MPEG format
The quality on it is very good for both Cable input and RCA input from my playstation. (i have no SVideo sources so I haven't tried that one)
You can use internal or external attachment to your video card.
It's small fits in any case

it's not much longer than the PCI slot is.
I've found it to be very very good.
And just recently they've finally released Win2000 beta drivers, I'm installing Win2k on my system in a few days so I'll let you know how that works out

I've heard some good and some bad.