It will depend on what TV you have as to which one you use (some TVs like the Pioneers have excellent scalers in them). Go to the Video Output Settings as PJPro says and use the Custom set up and make sure only 576p is ticked, then play a DVD and see what the picture is like. Then go back and choose Automatic and let it find the best native resolution for your TV. Then go into BD/DVD Settings and switch the DVD Upscaler on. Then play the same DVD and see what the picture is like. Repeat as necessary and then go with whichever one you think looks best.