While I don't have a PS2 or an Xbox, I have been using my Gamecube with my MSI Ti4400's video in and it works pretty well. Quality isn't _perfect_, but it's pretty damn good considering it's built in...also, half the quality loss may be the fault of the damn analog (even to svideo) output I'm doing from my Gamecube... I have yet to find a digital connector for it :|
I use a 30Kb program called TV Viewer, it's a 30 day trial with an inexpensive option to purchase. It does the trick, as should any program that can access the WDM stuff (or whatever you call it
I don't have a link but just do a google search, if you can't find it I'll try to dig it up. It was posted in these forums though...