Also, this may seem obvious, but make sure you know the resolution of your TV -- many flat panel HDTVs only support 720p maximum. Make sure that you go to the System blade on the 360 dashboard -> Console Setings -->Display and set it to match your TV. Also, I highly recommend setting the Reference level to Expanded to get better color depth. This doesn't really address the response time issue, but it will help you get the best image quality. Again, you may know all this, but I find many people are still learning all this stuff.

I've got an Elite that I bought on release day. Zero problems, all joy.