Well I watched a couple of my favorite episodes last night. I have this series in DVD, HD-DVD, and now Blu Ray. For all that don't have the series in any format or in DVD, buy it! I watched last night on my humble Samsung 1080p dlp, with my bd30 ( for Blu ) and my Onkyo d805 ( for HD-DVD ), for sound I used my Onkyo 805 receiver. For sound, to me there is absolutely no difference between Blu & HD-DVD, the sound is awesome! Now for the picture, I found the HD-DVD very, very slightly sharper but this really subjective. I don't know why this would be, not sure if it is the players or my imagination, but I noticed it immediately on scenes I've seen a zillion times. Now, this is really minor, and I would not be detered from buying the Blu set if you can find a good deal and already own the HD-DVD. This is just one mans opinion.