Seems like the majority of Xbox games, (newer ones anyway) are 480p, but there are some 720p and 1080i games. I have my Xbox set with yes to all three formats. Seems to me like you would want to use the highest native resolution the Xbox would output. But I have my Xbox switching thru my Denon 2805 with high bandwidth component connections, and component connections to my Sony 55" LCD RPTV. Make sure you get the Xbox hi def hook up pack with optical digital audio out. It's the only way you will get true DD 5.1 game sound. With my Axiom M22ti's, VP150 center and SVS PC Ultra subwoofer, gaming is a TOTALLY different experience!!