is it better to burn a movie on a dvd and play it or is it ebtter to play it streaming through my network. what i really mean is what is streaming over ethernet cable like compared to composute, compnent, dmi, hdmi, s-video? is it a high defintion picture because of the band widht the category 5 e cable has ( what i am using)

How fast your connection has nothing to do with how clear the image is. If the video was encoded to play at X rate, then it will play at X rate if you are streaming it off a nework connection, or playing it from a DVD. If the connection is too slow, then you will notice dropped frames. The video will not get more fuzzy as the connection slows down.

In short, there is no difference in quality between playing a DVD in the XBox drive, or streaming it across the network.