Do you have any analog sources?
Um...yea, my Gamecube, Dreamcast and other assorted games are analog. And the 5.1 inputs for the DVD-A.
As far as the Xbox versus PS2 goes it all depends upon the games you're looking for. Xbox is great for 5.1 gaming but PS2 has the better software library. Check out the video game forum here on HTF for more info.