clayman88 said:
Like Hi Ho mentioned, your tv is going to scale whatever it is given to it's own native resolution. What you'll need to determine is whether your sat box or your tv does a better job of scaling & interlacing/deinterlacing the signal.
That's a big BINGO! The best thing to do is to try all possible resolutions to the display including 'native' resolution, then see which works best. Each and every display responds a bit differently and some do a fantastic job with 1080i and bring it down to 768p or 720p beautifully, while other displays work best with 720p coming in.
Others just handle the original formats (480i, 480p, 720p, 1080i) great and convert them all to the screens native format with barely a hiccup so you truly get the best possible display from those formats.
I personally set my output to 1080i on my cable box to feed my Sampo 50" plasma and Panny front projection system. Seems to work well enough.